Bondline - User contributions [en]

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:57:41Z

Boris Velednitsky: /* Camlocks on the leading edge of the top cowl */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.
The cowling is available from AuCountry Aviation -
www.aucountry.com
. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 
The following web sites helped me to figure it out:
http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm
- solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf
- CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <
https://www.aircraftspruce.com/catalog/hapages/cherrymax.php
> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on
www.cessnadirect.com
. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon -
http://www.amazon.com/gp/product/B001DT2ZTG
- they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon:
http://www.amazon.com/gp/product/B0028081GK
(Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here:
http://www.bondline.org/wiki/Nose_Strut
. Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 
==Pre-installation Engine Alignment==
I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 
<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>
Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail:
http://forums.matronics.com/viewtopic.php?t=81902
 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!

http://www.ihandysoft.com/level_free.html
 
Here is the result:
<gallery>
File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 
==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side
File:Top Right Corner 2.jpg|Top Right Corner
File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.
==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer:
http://forums.matronics.com/viewtopic.php?t=82085

 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 
==Cutting a hole for PowerFlow exhaust==
The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>
==Cutting a hole for Landing Light==
Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 
==Camlocks on the leading edge of the top cowl==
Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 
 
<gallery>
File:LeadingEdgeCamlock.jpg | Camlock on the leading edge of the top cowl
File:LeadingEdgeCamlockCloseup.jpg |Camlock on the leading edge – closeup
File:LeadingEdgeCamlockReceptacle.jpg |Leading Edge Camlock Receptacle
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 
It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 
Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 
In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 
Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 
> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 
Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com
Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:56:59Z

Boris Velednitsky:

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.
The cowling is available from AuCountry Aviation -
www.aucountry.com
. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 
The following web sites helped me to figure it out:
http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm
- solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf
- CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <
https://www.aircraftspruce.com/catalog/hapages/cherrymax.php
> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on
www.cessnadirect.com
. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon -
http://www.amazon.com/gp/product/B001DT2ZTG
- they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon:
http://www.amazon.com/gp/product/B0028081GK
(Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here:
http://www.bondline.org/wiki/Nose_Strut
. Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 
==Pre-installation Engine Alignment==
I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 
<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>
Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail:
http://forums.matronics.com/viewtopic.php?t=81902
 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!

http://www.ihandysoft.com/level_free.html
 
Here is the result:
<gallery>
File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 
==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side
File:Top Right Corner 2.jpg|Top Right Corner
File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.
==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer:
http://forums.matronics.com/viewtopic.php?t=82085

 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 
==Cutting a hole for PowerFlow exhaust==
The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>
==Cutting a hole for Landing Light==
Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 
==Camlocks on the leading edge of the top cowl==
Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 
 
<gallery>
File:First LeadingEdgeCamlock.jpg | Camlock on the leading edge of the top cowl
File:First LeadingEdgeCamlockCloseup.jpg |Camlock on the leading edge – closeup
File:Final LeadingEdgeCamlockReceptacle.jpg |Leading Edge Camlock Receptacle
</gallery>
==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 
It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 
Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 
In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 
Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 
> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 
Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com
Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:55:05Z

Boris Velednitsky:

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.
The cowling is available from AuCountry Aviation - www.aucountry.com. 
==Hardware== The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 
The following web sites helped me to figure it out:
http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 
http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 
Here is my parts list(to complement, not replace the list in the Instructions): # Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. # Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. # Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 # Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. # Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. # Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. # Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench) # Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way. # Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.# to be continued. 
==Pre-installation Engine Alignment==
I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 
<gallery>File:Bottom.jpg|BottmFile:Top.jpg|TopFile:Pilot side.jpg|Pilot sideFile:Passenger side.jpg|Passenger side</gallery>
Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free! http://www.ihandysoft.com/level_free.html Here is the result:<gallery>
File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-File:Engine angle 2.jpg|Measuring engine angle</gallery> So my engine is pointing half a degree up. Should I start worrying? However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 
==First Fitting==Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place. <gallery>File:Side View 2.jpg|Side ViewFile:Top 2.jpg|TopFile:Bottom 2.jpg|BottomFile:Passenger side 2.jpg|Passenger sideFile:Pilot Side 2.jpg|Pilot Side
File:Top Right Corner 2.jpg|Top Right Corner
File:Top Left Corner 2.jpg|Top Left CornerFile:Bottom Right Corner 2.jpg|Bottom Right CornerFile:Bottom Left Corner 2.jpg|Bottom Left Corner</gallery> The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.
==Trimming and drilling screw holes==As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all. 
==Cutting a hole for PowerFlow exhaust==
The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something? Dremel proved itself useful. To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.<gallery>File:First Cut.jpg|First Cut compared with PowerFlow TemplateFile:Final Cut.jpg|Final Cut, should have been perfectly oval</gallery>
==Cutting a hole for Landing Light==
Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
==Camlocks on the leading edge of the top cowl==
Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 
<gallery>File:First LeadingEdgeCamlock.jpg | Camlock on the leading edge of the top cowlFile:First LeadingEdgeCamlockCloseup.jpg |Camlock on the leading edge – closeupFile:Final LeadingEdgeCamlockReceptacle.jpg |Leading Edge Camlock Receptacle</gallery>
==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==START QUOTE \>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 
It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 
Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 
> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 
In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 
Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 
> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 
Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. --Bob Steward Birmingham, AL END QUOTE ==Questions, Comments, Suggestions?==Please e-mail to bvnj at yahoo dot com
Gil Alexander If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.
http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:53:38Z

Boris Velednitsky:

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.
The cowling is available from AuCountry Aviation -
www.aucountry.com
. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 
The following web sites helped me to figure it out:
http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm
- solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf
- CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <
https://www.aircraftspruce.com/catalog/hapages/cherrymax.php
> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on
www.cessnadirect.com
. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon -
http://www.amazon.com/gp/product/B001DT2ZTG
- they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon:
http://www.amazon.com/gp/product/B0028081GK
(Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here:
http://www.bondline.org/wiki/Nose_Strut
. Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 
==Pre-installation Engine Alignment==
I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 
<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>
Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail:
http://forums.matronics.com/viewtopic.php?t=81902
 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!

http://www.ihandysoft.com/level_free.html
 
Here is the result:
<gallery>
File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 
==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side
File:Top Right Corner 2.jpg|Top Right Corner
File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.
==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer:
http://forums.matronics.com/viewtopic.php?t=82085

 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 
==Cutting a hole for PowerFlow exhaust==
The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>
==Cutting a hole for Landing Light==
Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 
==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 
It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 
Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 
In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 
Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 
> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 
Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com
Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:52:16Z

Boris Velednitsky: Replaced content with "This page is to document the steps I am taking in the process of installation of Jaguar Cowl."

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:22:25Z

Boris Velednitsky: /* Camlocks on the leading edge of the top cowl */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Camlocks on the leading edge of the top cowl==

Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 

<gallery>

File:First LeadingEdgeCamlock.jpg | Camlock on the leading edge of the top cowl

</gallery>

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:21:54Z

Boris Velednitsky: /* Camlocks on the leading edge of the top cowl */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Camlocks on the leading edge of the top cowl==

Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 

<gallery>

File:First LeadingEdgeCamlock.jpg | Camlock on the leading edge of the top cowl

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:20:45Z

Boris Velednitsky: /* Camlocks on the leading edge of the top cowl */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Camlocks on the leading edge of the top cowl==

Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 

<gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:18:53Z

Boris Velednitsky: /* Camlocks on the leading edge of the top cowl */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Camlocks on the leading edge of the top cowl==

Installation instructions call for a screw and a nutplate on the leading edge of the top cowl because the standard camlock receptacle sticks out too far into the cooling air stream, but with Gary’s permissions I installed a camlock. I did find a guy in Belgium who offered to sell me 2 low profile camlock receptacles for $25 each, but I figured that’s too much, and made a couple of my own receptacles which work well with the shortest camlock I could find. 

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

Installing AuCountry Jaguar Cowl on my AA5-B

2012-09-07T20:12:48Z

Boris Velednitsky: /* Cutting a hole for Landing Light */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Camlocks on the leading edge of the top cowl==

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Gil Alexander 
If you are not sure about the installation of solid rivets, finding a RV builder in your local EAA Chapter would be a good reference. Vans Aircraft has a copy of the Mil-Spec for rivet installation and it can help you identify the difference between a good rivet and a bad rivet. I have found a lot of builders will rework rivets that are not "perfect" but still are acceptable for structural purposes.

http://www.vansaircraft.com/public/Specs.htm

File:LeadingEdgeCamlockReceptacle.jpg

2012-09-07T20:02:24Z

Boris Velednitsky: Leading Edge Camlock Receptacle

Leading Edge Camlock Receptacle

File:LeadingEdgeCamlockCloseup.jpg

2012-09-07T20:01:36Z

Boris Velednitsky: Camlock on the leading edge - closeup

Camlock on the leading edge - closeup

File:LeadingEdgeCamlock.jpg

2012-09-07T20:00:35Z

Boris Velednitsky: Camlock on the leading edge of the top cowl

Camlock on the leading edge of the top cowl

FunFlyinLocations

2011-08-23T01:09:47Z

Boris Velednitsky:

'''What is your favorite Fly-in location? Here are some of ours:'''

'''ALABAMA'''
:[http://www.airnav.com/airport/KEKY EKY] Bessemer, AL '''The Hangar''', a new on-field restaurant. [[user:Bob_Steward|Bob Steward]] says: "I've been to this Sports bar with aviation theme, good $100 burger, etc." Region 4 had a fly-in Saturday Feb 21 @ lunch. 9 Aircraft and 18 attendees, reviews were very positive, with requests to meet there again.

'''ARKANSAS'''

:[http://www.airnav.com/airport/KMEZ MEZ] Mena, AR Aircraft paint and engine shops -- of interest if you are thinking paint/engine/upholstery. [[User:scoffey|Stephen Coffey]] Be advised, after a long flight, there isn't a beer for MILES. And the Sun Country Inn is much newer/nicer than the other options if you get the "privilege" of getting socked in for 3 days like I did. [[user:Bob_Steward|Bob Steward]] says: "I can second the recommendation for Sun Country Inn. I've stayed there and at 2 other local motels while working at the Mena Airport on various Grummans. Lime Tree has a nice restaurant (Sun Country has no food), but the building is older and the rooms less nice than Sun Country. I ate breakfast at Lime Tree multiple times."

'''FLORIDA'''

:[http://www.airnav.com/airport/55J 55J] Fernandina Beach / Amelia Island. [[User:scoffey|Stephen Coffey]] The Ritz there occasionally does last minute specials at a good price. The airport is a 5 minute cab ride to the hotel. Downtown is kinda quaint and cool. Quick and easy SE get away.

'''GEORGIA'''

:[http://www.airnav.com/airport/KFFC FFC] Falcon Field Peachtree City, GA '''Aircraft Spruce East''', '''Dixie Wing of Confederate Air Force Restoration Center'''

:[http://www.airnav.com/airport/KLZU LZU] Gwinnett County Lawrenceville, GA '''EAA 690 Pancake Breakfast''' 1st Saturday every month. Program follows @ 10:30

:[http://www.airnav.com/airport/KPDK PDK] Dekalb-Peachtree in North Atlanta, GA '''Downwind Restaurant''' (on the second story of the Administration Building next to Epps Air Service). Has balcony/deck for outdoor dining when Wx is good.

:[http://www.airnav.com/airport/KRYY RYY] Cobb County Airport-Mc Collum Field '''Elevation Chophouse''' [[User:scoffey|Stephen Coffey]] "Higher end food, but pretty good. Nice HUGE glass wall facing the runway."

'''KENTUCKY'''

:[http://www.airnav.com/airport/KOWB OWB] Owensboro, KY '''Moonlight BBQ''' (not on field, only a short drive), '''Bill and Carol Scott's Precision Engine''' shop. [[user:Bob_Steward|Bob Steward]] says: "I visit Moonlight BBQ everytime I stop by Precision Engine to see Bill and Carol."

'''NEW JERSEY'''
:[http://www.airnav.com/airport/12N 12N] Aeroflex, NJ '''Kittatiny State Park''' Nice biking and hiking trails start at the airport, Boating - lake 100 yards from the runway. Bring your own inflatable boat or bicycles.

Installing AuCountry Jaguar Cowl on my AA5-B

2011-07-05T18:10:05Z

Boris Velednitsky: /* Cutting a hole for PowerFlow exhaust */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-07-05T18:07:10Z

Boris Velednitsky: /* Cutting a hole for PowerFlow exhaust */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Cutting a hole for Landing Light==

Another item not covered in the install instructions. Gary provided the line to cut but in e-mails he first said that the line on my cowl is off by 1/4", then he said it wasn't my cowl, but another guys cowl, and mine has the line in the right place. Just to be safe I left a 1/2 inch safety margin and cut a much smaller hole at first. Then I put the cowl on the plane and tried to find the best fit. Gary mentioned that there is very little space between the light and the starter, but I got a Sky-Tec starter and there was enough space between starter, but very little space between the PowerFlow 4 to 1 collector, so I had to move the light housing forward a little from Gary's line. I hope I can still aim the light somewhere in the vicinity of runway! Then I cut a couple of 1/8 holes and clecoed the housing to the cowl, removed the light, drew the outline of the housing on the cowl from inside the housing and cut along the line. My hole ended up pretty close to Gary's line, but it is a bit wider and a bit shorter. 
 

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-07-05T17:48:04Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. I got brad point bits from Amazon - http://www.amazon.com/gp/product/B001DT2ZTG - they make fairly smooth holes in fiberglass. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-23T03:32:10Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates to joggle, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Minimum order is 1/8 lb - a lot of extra rivets. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. To attach 2 nutplates for hinge attachment, need Spruce part AN426AD-3-5 as the cowl thickness there measures 0.157 and 0.197 for the total rivet length of 0.286 and 0.326 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-23T03:18:21Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling and 2 more to hold the hinge to the lower cowling. Total 16. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-16T15:51:53Z

Boris Velednitsky: /* Cutting a hole for PowerFlow exhaust */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting the hole. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is wasted. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-16T15:40:30Z

Boris Velednitsky: /* Cutting a hole for PowerFlow exhaust */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting a hole in the standard cowl. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is lost. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:First Cut.jpg|First Cut compared with PowerFlow Template
File:Final Cut.jpg|Final Cut, should have been perfectly oval
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

File:Final Cut.jpg

2011-06-16T15:38:21Z

Boris Velednitsky:

File:First Cut.jpg

2011-06-16T15:38:06Z

Boris Velednitsky:

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-16T15:34:27Z

Boris Velednitsky: /* Trimming and drilling screw holes */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

==Cutting a hole for PowerFlow exhaust==

The Cowl instructions don't cover this. I guess, this means that one should follow the PowerFlow instructions for cutting a hole in the standard cowl. The template in PowerFlow instructions shows a semi-oval hole, and on another page it shows how to make a removable "door" between that hole and firewall to make cowl removal easier. 
Question to current PowerFlow owners: How difficult it is to remove the standard cowl without that "door"? 
As for Jaguar cowl, turns out, it is impossible to remove the right bottom cowl if you have just an oval hole and want to keep the muffler in place. I checked with Gary and he said he just extends the hole to the firewall and puts an extra nutplate to replace the one that is lost. I have an aversion to cutting so I came up with an alternate method. I figured I could just remove the PowerFlow muffler instead. It takes me 2 minutes to remove 3 bolts on the muffler ball joint and 1 bolt on the support arm, and 3 minutes to put it all back. The cotter pins will be a pain, though. I wonder if there are easy-on easy-off cotter pints, like a safety pin, or something?
 
Dremel proved itself useful. It probably could be done with jigsaw blade and round file, but would require a lot more elbow grease. 
To avoid cutting too big of a hole, I disconnected the muffler and cut the hole just big enough to fit the muffler through - see picures. Then I started enlarging it gradually with Dremel filing drum as I was trying to align the muffler with the intermediate pipe. Took a long time - about 4 hours, but the hole came up pretty close to what I wanted, except maybe in one spot the gap is a little larger.
<gallery>
File:Example.jpg|Caption1
File:Example.jpg|Caption2
</gallery>

==Full Text of Bob's e-mail regarding the engine thrust angle alignment:==
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE 
==Questions, Comments, Suggestions?==
Please e-mail to bvnj at yahoo dot com

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-16T14:58:41Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08 which looks identical to MS21048-L-08, but Gary explained that MS21047L08 will rust and MS21048-L-08 will not. 
# Solid rivets to attach those nutplates, countersunk 3/32". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T18:14:57Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. According to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 15/32 is .0037" less than 12 mm and 5/8 is .0049 less than 16mm. I will see if they work. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:46:48Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. Acording to installation instructions(link above) you need 12mm drill bit for the gromet and 16mm drill bit for the receptacle. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:30:19Z

Boris Velednitsky: /* Hardware */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# Two 1 inch bolts with the same thread as propeller bolts - to hold the spinner backplate in place while fitting the cowl. From local hardware store.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:28:09Z

Boris Velednitsky: /* First Fitting */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I would remove the spinner back plate which was held by two 1 inch bolts from hadware store and would screw one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:25:59Z

Boris Velednitsky: /* First Fitting */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
In the process of trimming I had to remove and re-install the bottom halves several times. I found it easier to remove the halves clecoed together as one piece instead of removing 12 clecoes every time. I had no exhaust, no nose strut and before removing the cowl I had to remove the spinner back plate which was held by two 1 inch bolts from hadware store and then screwed one of those bolts back to make sure the flywheel would stay in place.
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:11:13Z

Boris Velednitsky: /* Pre-installation Engine Alignment */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary helped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:08:34Z

Boris Velednitsky: /* Pre-installation Engine Alignment */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary heped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Engine angle 1.jpg|Calibrating - no plane leveling needed, just press -calibrate-
File:Engine angle 2.jpg|Measuring engine angle
</gallery>
 
So my engine is pointing half a degree up. Should I start worrying? 
 

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

File:Engine angle 2.jpg

2011-06-12T17:02:23Z

Boris Velednitsky:

File:Engine angle 1.jpg

2011-06-12T17:02:03Z

Boris Velednitsky:

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-12T17:01:35Z

Boris Velednitsky:

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary heped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
A few days later I figured I don't need a $200 digital level to check the engine vertical angle. My iPhone has an accelerometer and a quick app search confirmed - there is a digital level app, and it's even free!
http://www.ihandysoft.com/level_free.html 
Here is the result:
<gallery>

File:Example.jpg|Caption1
File:Example.jpg|Caption2
</gallery>

However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T18:57:53Z

Boris Velednitsky: /* Trimming and drilling screw holes */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T18:44:11Z

Boris Velednitsky: /* First Fitting */

This page is to document the steps I am taking in the process of installation of Jaguar Cowl.

The cowling is available from AuCountry Aviation - www.aucountry.com. 

==Hardware==

The Cowling comes with the Installation Instructions which have a list of Tools and Harware reqirements, but I still had to spend many hours fuguring out exactly where to buy parts, how many and what exact sizes to order. 

The following web sites helped me to figure it out:

http://bobmay.astronomy.net/misc/drillchart.htm - helpes to figure out the numbered drill bit sizes in relation to fractional rivet sizes. 

http://www.hansonrivet.com/w06.htm - solid rivet installation guide. I haven't worked with solid rivets before. Notice suggested Clinch Allowance at the bottom of the chart. It helps to determine the proper rivet length. 

http://www.afscamloc.net/xua/downloads/4002%20Series.pdf - CamLoc selection and installation instructions. 

Here is my parts list(to complement, not replace the list in the Instructions): 
# Rivets to attach the upper cowl halves to the hinge - cherry-max countersunk head 1/8". 38 rivets - 19 on each side. Install manual asks for CR3212-4-2. According to Aircraft spruce <https://www.aircraftspruce.com/catalog/hapages/cherrymax.php> those have grip range 0.63 to .125. I measured hinge thickness + upper cowl thickness = 0.142". Maybe CR3212-4-3 is better? Ordered CR3212-4-2 anyway. Those require drill #30, Aircraft Spruce part 12-04217 and #30 countersink, Aircraft Spruce part 12-00880. The cage for countersinks is Spruce part 12-00940. 
# Nutplates to hold lower cowling halves together. 9 on the bottom + 3 on top. There are also 2 to hold upper cowling halves to lower cowling. Total 14. Install manual asks for MS21048-L-08. I believe Manual says 'countersunk' by mistake. I found those on www.cessnadirect.com. AircraftSpruce has MS21047L08. Aren't they the same? 
# Solid rivets to attach those nutplates, countersunk 3/26". The lower cowl joggle thickness measures between 0.07 and 0.09", the nutplate thickness is 0.035", so the total grip is between 0.105 and 0.125. The clench allowance for 3/32" is 0.094. So need Aircraft Spruce part AN426AD-3-3.5. Ordered 1/8 lb - a lot of rivets to practice on scrap aluminum. Require drill #40, Aircraft spruce part 12-04214 and #40 countersink part 12-00881. 
# Camloc part according to Install Instructions, except they leave out the Camloc receptacles, Aircraft Spruce part 214-16N. Those receptacles require 1/8" rivets. The receptacle plate depth is 0.091, the lower cowl joggle thickness is between 0.114 and 0.134, the 1/8" rivet clinch allowance is .094, so total rivet length between 0.3 and 0.32. Ordered Aircraft Spruce part AN426AD-4-5. Also need Camloc pliers, Spruce part 12-01475, although I used a cut split washer and Cleco pliers instead. 
# Rivet Squeezer, Aircraft Spruce part 12-01462, and two squeezer dies part 12-01466. 
# Clecos, Spruce part 12-01138. 12 to hold lower cowl halves together, 19 to hold the upper cowl halves to the hinge and 10 to hold the upper halves to lower cowl - 31 all together. Cleco pliers, Spruce part 12-10105. 
# Engine hoist, if you will need to adjust the engine alignment. I borrowed one. Torque wrench to torque the engine mounts to 40 ft-lb. I got one on Amazon: http://www.amazon.com/gp/product/B0028081GK (Gorilla Automotive TW605 Torque Wrench)
# Lever to remove the nose strut unless you are prepared to cut off the nose strut fairing boot. I borrowed one and later made my own because the borrowed one was too loose. See instructions here: http://www.bondline.org/wiki/Nose_Strut . Zinc chromate primer - to put the strut back. I orderd one from Fletchair and got a zinc phosphate primer instead. Hope it works the same way.
# to be continued. 

==Pre-installation Engine Alignment==

I have just installed a Ly-Con overhauled engine with the new Lord engine mounts with one spacer on each mount. Before installing the Jaguar cowl I am checking the fit against the original cowl. The old bottom Lord mounts were leaking and the spinner was sagging agains the nose bowl. Now the spinner is hanging a little high and a little to the right - see pictures. 

<gallery>
File:Bottom.jpg|Bottm
File:Top.jpg|Top
File:Pilot side.jpg|Pilot side
File:Passenger side.jpg|Passenger side
</gallery>

Not sure how to go about engine alignment I asked for help on Team Grumman. Bob and Gary heped with advice but they didn't quite agree with each other. 
Bob: \"...The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> ...\" Full text of Bob's e-mail at the end of the page 
Gary's experience is that engine mounts don't necessarily sag with time and that engine rises agains the cowl in flight. Here is Gary's e-mail: http://forums.matronics.com/viewtopic.php?t=81902 
 

I decided to take a middle road - leave the vertical alignment as is and center the Jaguar cowl vertically with the spinner back plate. 
However I was more concerned with horizontal alignment. As Bob's e-mail at the bottom of this page suggests, there is no direct way to measure the horizontal alignment. The consensus seems to be that the original cowl is the best available reference point. I vaguely remembered that I sometimes I had to hold a little left rudder in cruise, so I added one spacer on the top right mount and one spacer on the bottom right mount. This over-corrected the alignment, but ony a tiny little bit. Maybe I should have used half-thickness spacers, but I don't have any right now. If I will end up holding the right rudder in cruise, I will replace full with half-thickness, but for now I will just align the Jaguar cowl a little tiny bit to the right of the spinner, in case I have to go to half-thickness spacers on the right. 

==First Fitting==
Install instructions don't mention this, but you have to remove the nose strut fairing boot. If you don't want to cut it off, you will have to remove the nose strut. 
Here is the first fitting. The cowl lined up nicely. Only 2 bolt holes are drilled and no trimming yet. The install manual calls for 3/16 drill for screw holes, I am using the 5/32. This gives me a tight fit and a little more room for error. 
To hold the cowling in place I cut a couple of wooden planks to size and jammed them under the bottom corners by the firewall - see pictures. 
<gallery>
File:Side View 2.jpg|Side View
File:Top 2.jpg|Top
File:Bottom 2.jpg|Bottom
File:Passenger side 2.jpg|Passenger side
File:Pilot Side 2.jpg|Pilot Side

File:Top Right Corner 2.jpg|Top Right Corner

File:Top Left Corner 2.jpg|Top Left Corner
File:Bottom Right Corner 2.jpg|Bottom Right Corner
File:Bottom Left Corner 2.jpg|Bottom Left Corner
</gallery> 
The last picture - Bottom Left Corner - gave me a little worry at first - the cowl seemed alomst 1/2 inch wider then the fuselage. But this gap dissapeared after I put in the bottom side corner screws.

==Trimming and drilling screw holes==
As I mentioned, I am using the 5/32 drill bit for screw holes - works well for me. 
I ended up enlarging a couple of screw holes for a correct fit, but they are still covered completely by the button head screws so I am not worried. Just in case, I asked Gary for epoxy repair materials and instructions and here is his answer: http://forums.matronics.com/viewtopic.php?t=82085
 Installation instructions recommend using Dremel for trimming so I bought a Dremel. Not needed. I did all trimming with my dry wall sanding block and a pack of 100 dry wall sand paper. Fresh sand paper goes thru the fiberglass like a knife thru butter and you have less chance to screw up and cut too much. 
On the Pilot side I ended up trimming to Gary's trim line but on the Passenger side I hardly had to trim at all.
 
After installing the bootom corner screws the gap at the bottom corners dissapeared,
'''However now the nose strut shock absorbers are riding on the Jaguar cowl fiberglass nose strut fairing.''' I expected there to be some gap but now there is no gap at all. Question to Gary - did you have this problem in earlier installs? How did you deal with this?

 

====Full Text of Bob's e-mail regarding the engine thrust angle alignment:====
START QUOTE 
\>Please take a look. I wonder if you could please help me regarding the spacers on engine mounts. I just bought a set of new Lord engine mounts. The old bottom ones were leaking and the spinner was sagging about 1/2 inch against the nose bowl rim. Now I have placed 1 spacer on each(as it was before) and torqued it per manual, 40 lb-feet. Before fitting the new cowl I tried the old one to check and found that engine is now hanging a little high against the nose bowl and a little to the right. 

The method we used before Gary sent out his cowl was to align the spinner with the factory cowling, leaving it perhaps 3/8" high with new mounts, as they sag with age, and in a few months they'd be allowing the spinner to align very closely with the nose bowl. Some argue that the engine will rise up when in flight and pulling against the mount, and it will overcome the sagging in the rubber mounts. This is damned hard to measure in flight. <G> Some photographic evidence may be the source of this contention. 

It is required to have 1 full thickness spacer between each lower mount and the engine case. It has to do with clearance of the large mount cups from the engine. This isn't an issue with the Cheetah/Traveler with its smaller cups. Any additional spacers on any of the 4 mount points are optional and "as required" to center the spinner. 

Lord makes, though they are hard to find, 1/2 thickness spacers, which can be used to jack the engine around as needed to center the spinner better than a full thickness one might. I've had them made from AN970-7 washers on occasion when my supply of the Lord half thickness spacers ran out. Any machine shop with a surface grinder can make you some. Etch and prime before installing. 

> My question is - should I try to add spacers to align the spinner to the old cowl before I fit the new cowl, and if you think I should, then why? In other words, why aligning to the old cowl would give me a better thrust angle then relying on the angle provided by the engine mount together with the set of new properly torqued Lord mounts? 

In theory the cowling was built on a jig at the factory and the firewall (Station 50) is the reference for all measurements on the plane, so the jigged cowl mated to the firewall by Grumman would give the proper relationship to the nose bowl opening. 

Gary says his measurements of the engines, when shimmed to align the nose bowl and spinner, are all over the place with respect to the Thrust Angle of the engine (reputed to be 3 degrees down). I've just used the maintenance manual method in the past, and trusted that the factory jigs were accurate. 
If you can determine an accurate reference point (canopy rails are used to level the fuselage fore-aft and laterally), you could begin to measure the actual Thrust Angle of your engine and play with aligning it differently than the Maintenance Manual method suggests. Caution is suggested here, as we are REQUIRED by FAR 43.13 to use the Maintenance Manual methods and tools. If Gary's instructions specifically instruct you to alter the engine Thrust Angle, you can claim that the STC then supercedes the 43.13 requirement. However Gary's anecdotal evidence of differences in various planes, and his discussion on TeamGrumman is not an FAA approved source of data. The factory had good reason to set the engine Thrust Angle down and to the side, and changing it will alter the flying characteristics, possibly in a way that is undesirable, and even unsafe. 

> I guess the left/right angle could be checked by measuring the distance from propeller tips to wings when prop is positioned horizontally. I guess one should try to make sure they are equal. Or not? 

Your assumption that the distance from the prop tips to the wing (tips) should be equal is incorrect. Align per the Maintenance Manual and then take the cowl off and measure back to the firewall from the prop, and you'll see that the engine is TURNED with respect to the firewall. Laying the nose bowl on the ground will quickly show you how offset it is, too. Note that the spinner opening flange is TILTED quite a bit, not only vertically, but to the side as well. 
--Bob Steward 
Birmingham, AL END QUOTE

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T18:39:29Z

Boris Velednitsky: /* Trimming and drilling screw holes */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T18:36:00Z

Boris Velednitsky: /* First Fitting */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T18:34:49Z

Boris Velednitsky: /* Hardware */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:59:11Z

Boris Velednitsky: /* Trimming and drilling screw holes */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:56:17Z

Boris Velednitsky: /* Trimming and drilling screw holes */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:48:02Z

Boris Velednitsky: /* First Fitting */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:40:30Z

Boris Velednitsky: /* Hardware */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:32:14Z

Boris Velednitsky: /* First Fitting */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:17:46Z

Boris Velednitsky: /* First Fitting */

Installing AuCountry Jaguar Cowl on my AA5-B

2011-06-11T17:11:27Z

Boris Velednitsky: /* Pre-installation Engine Alignment */

File:Top Right Corner 2.jpg

2011-06-11T17:07:01Z

Boris Velednitsky:

File:Top Left Corner 2.jpg

2011-06-11T17:06:51Z

Boris Velednitsky:

File:Top 2.jpg

2011-06-11T17:06:38Z

Boris Velednitsky: