https://bondline.org/api.php?action=feedcontributions&feedformat=atom&user=24.221.130.0%2F24Bondline - User contributions [en]2026-11-11T01:58:03ZUser contributionsMediaWiki 1.46.2https://bondline.org/index.php?title=Rigging_Checks_and_adjustments&diff=1488Rigging Checks and adjustments2006-01-14T18:23:03Z<p>24.221.130.104: </p>
<hr />
<div>'''Rigging Checks'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench.jpg]]<br />
<br />
'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''<br />
<br />
Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.<br />
<br />
Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.<br />
<br />
The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998-- at the first Cody Convention when I spearheaded the effort to start the rigging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!<br />
<br />
Significant performance changes can be obtained by removing the errors and getting the plane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.<br />
<br />
<br />
'''Rigging Adjustments'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]<br />
<br />
'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''<br />
<br />
After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool I've found), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.<br />
<br />
The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.<br />
<br />
Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel. If the flap motor and drive assembly is moving the flaps too much or too little travel, then its probably a limit switch problem, either adjustment or failure. If the correct amount of travel in total degrees of movement is correct, then the flap drive mechanicsm can be adjusted via the heim joints on each side to place the flap in the correct position at the UP stop. An note on adjusting the flaps, many planes have excessive play in the flaps. This seems especially prevalent on the AA-5 series, which have a more complex flap drive and more places to allow wear and increase the play. This would also be a good time to verify that the aileron torque tube is accurately centered within the flap torque tube. This keeps the pins on the special flap drive bolts from possibly wearing a groove in the aileron torque tube.<br />
<br />
Aileron rigging is subject to several possible faults. The cables can be incorrectly tensioned, the adjustment of the front cables to the control yoke and be miss-ajusted relative to the aft "turn around" cable that connects the 2 cables from the yokes, the aileron outboard bracket can be bent or damaged, and the outboard aileron bracket can be positioned incorrectly on the aft spar.<br />
<br />
Cable tensioning requires a cable tensiometer, which ought to have its calibration checked, if you are unsure of its testing and certification status. The basic operation is to clamp the tensiometer onto the cable in question and read the tension on the scale appropriate for the diameter of the cable. Adjustments are made by removing the safety wire or locking clip that holds the turnbuckle such that it can not let the cables unscrew from its ends. The first thing one needs to know about turnbuckles is that they have RH threads on one end, and LH threads on the other, such that if one holds the cable ends, and rotate the turnbuckle, you will either loosen or tighten the cable tension. It is important that you not turn one cable to change the tension.<br />
<br />
The [http://www.aircraftspruce.com/pdf/catalog/Cat06142.pdf safety clips or the safety wire] are NOT to be reused, so be sure to have some on hand before you start. Additionally you will need to be familiar with the [http://avstop.com/AC/apgeneral/628b.html correct way to safety wire a turnbuckle], and you'd be surprised at the number of A&Ps that can't do it right without looking at the book. The advantage of the [http://www.aerocraftparts.com/ItemForm.aspx?item=MS21256-1&Category=78ec149d-ecef-4c56-8695-2a6e720af22d MS21256] ''{NOTE - the AA5s need MS21256-2 safety clips - the links given only point to MS21256-1 clips that are too short - call Fletchair}'' style safety clips is that they are quick and easy to install correctly, and they [http://avstop.com/AC/apgeneral/628a.html can be installed one-handed in a tight spot] where trying to wrap safety wire would be very difficult. I've seen a mix of turnbuckles installed on the fleet. Some have the groove in the threads for the safety clips, and some don't.<br />
<br />
<br />
<To be continued></div>24.221.130.104https://bondline.org/index.php?title=Rigging_Checks_and_adjustments&diff=1487Rigging Checks and adjustments2006-01-14T18:22:21Z<p>24.221.130.104: </p>
<hr />
<div>'''Rigging Checks'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench.jpg]]<br />
<br />
'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''<br />
<br />
Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.<br />
<br />
Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.<br />
<br />
The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998-- at the first Cody Convention when I spearheaded the effort to start the rigging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!<br />
<br />
Significant performance changes can be obtained by removing the errors and getting the plane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.<br />
<br />
<br />
'''Rigging Adjustments'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]<br />
<br />
'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''<br />
<br />
After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool I've found), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.<br />
<br />
The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.<br />
<br />
Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel. If the flap motor and drive assembly is moving the flaps too much or too little travel, then its probably a limit switch problem, either adjustment or failure. If the correct amount of travel in total degrees of movement is correct, then the flap drive mechanicsm can be adjusted via the heim joints on each side to place the flap in the correct position at the UP stop. An note on adjusting the flaps, many planes have excessive play in the flaps. This seems especially prevalent on the AA-5 series, which have a more complex flap drive and more places to allow wear and increase the play. This would also be a good time to verify that the aileron torque tube is accurately centered within the flap torque tube. This keeps the pins on the special flap drive bolts from possibly wearing a groove in the aileron torque tube.<br />
<br />
Aileron rigging is subject to several possible faults. The cables can be incorrectly tensioned, the adjustment of the front cables to the control yoke and be miss-ajusted relative to the aft "turn around" cable that connects the 2 cables from the yokes, the aileron outboard bracket can be bent or damaged, and the outboard aileron bracket can be positioned incorrectly on the aft spar.<br />
<br />
Cable tensioning requires a cable tensiometer, which ought to have its calibration checked, if you are unsure of its testing and certification status. The basic operation is to clamp the tensiometer onto the cable in question and read the tension on the scale appropriate for the diameter of the cable. Adjustments are made by removing the safety wire or locking clip that holds the turnbuckle such that it can not let the cables unscrew from its ends. The first thing one needs to know about turnbuckles is that they have RH threads on one end, and LH threads on the other, such that if one holds the cable ends, and rotate the turnbuckle, you will either loosen or tighten the cable tension. It is important that you not turn one cable to change the tension.<br />
<br />
The [http://www.aircraftspruce.com/pdf/catalog/Cat06142.pdf safety clips or the safety wire] are NOT to be reused, so be sure to have some on hand before you start. Additionally you will need to be familiar with the [http://avstop.com/AC/apgeneral/628b.html correct way to safety wire a turnbuckle], and you'd be surprised at the number of A&Ps that can't do it right without looking at the book. The advantage of the [http://www.aerocraftparts.com/ItemForm.aspx?item=MS21256-1&Category=78ec149d-ecef-4c56-8695-2a6e720af22d MS21256] ''{note - the AA5s need MS21256-2 safety clips - the link given only point to MS21256-1 clips that are too short - call Fletchair}'' style safety clips is that they are quick and easy to install correctly, and they [http://avstop.com/AC/apgeneral/628a.html can be installed one-handed in a tight spot] where trying to wrap safety wire would be very difficult. I've seen a mix of turnbuckles installed on the fleet. Some have the groove in the threads for the safety clips, and some don't.<br />
<br />
<br />
<To be continued></div>24.221.130.104https://bondline.org/index.php?title=Rigging_Checks_and_adjustments&diff=1486Rigging Checks and adjustments2006-01-14T18:21:42Z<p>24.221.130.104: </p>
<hr />
<div>'''Rigging Checks'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench.jpg]]<br />
<br />
'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''<br />
<br />
Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.<br />
<br />
Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.<br />
<br />
The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998-- at the first Cody Convention when I spearheaded the effort to start the rigging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!<br />
<br />
Significant performance changes can be obtained by removing the errors and getting the plane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.<br />
<br />
<br />
'''Rigging Adjustments'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]<br />
<br />
'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''<br />
<br />
After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool I've found), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.<br />
<br />
The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.<br />
<br />
Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel. If the flap motor and drive assembly is moving the flaps too much or too little travel, then its probably a limit switch problem, either adjustment or failure. If the correct amount of travel in total degrees of movement is correct, then the flap drive mechanicsm can be adjusted via the heim joints on each side to place the flap in the correct position at the UP stop. An note on adjusting the flaps, many planes have excessive play in the flaps. This seems especially prevalent on the AA-5 series, which have a more complex flap drive and more places to allow wear and increase the play. This would also be a good time to verify that the aileron torque tube is accurately centered within the flap torque tube. This keeps the pins on the special flap drive bolts from possibly wearing a groove in the aileron torque tube.<br />
<br />
Aileron rigging is subject to several possible faults. The cables can be incorrectly tensioned, the adjustment of the front cables to the control yoke and be miss-ajusted relative to the aft "turn around" cable that connects the 2 cables from the yokes, the aileron outboard bracket can be bent or damaged, and the outboard aileron bracket can be positioned incorrectly on the aft spar.<br />
<br />
Cable tensioning requires a cable tensiometer, which ought to have its calibration checked, if you are unsure of its testing and certification status. The basic operation is to clamp the tensiometer onto the cable in question and read the tension on the scale appropriate for the diameter of the cable. Adjustments are made by removing the safety wire or locking clip that holds the turnbuckle such that it can not let the cables unscrew from its ends. The first thing one needs to know about turnbuckles is that they have RH threads on one end, and LH threads on the other, such that if one holds the cable ends, and rotate the turnbuckle, you will either loosen or tighten the cable tension. It is important that you not turn one cable to change the tension.<br />
<br />
The [http://www.aircraftspruce.com/pdf/catalog/Cat06142.pdf safety clips or the safety wire] are NOT to be reused, so be sure to have some on hand before you start. Additionally you will need to be familiar with the [http://avstop.com/AC/apgeneral/628b.html correct way to safety wire a turnbuckle], and you'd be surprised at the number of A&Ps that can't do it right without looking at the book. The advantage of the [http://www.aerocraftparts.com/ItemForm.aspx?item=MS21256-1&Category=78ec149d-ecef-4c56-8695-2a6e720af22d MS21256] {note - the AA5s need MS21256-2 safety clips - the link given only point to MS21256-1 clips that are too short - call Fletchair} style safety clips is that they are quick and easy to install correctly, and they [http://avstop.com/AC/apgeneral/628a.html can be installed one-handed in a tight spot] where trying to wrap safety wire would be very difficult. I've seen a mix of turnbuckles installed on the fleet. Some have the groove in the threads for the safety clips, and some don't.<br />
<br />
<br />
<To be continued></div>24.221.130.104https://bondline.org/index.php?title=Rigging_Checks_and_adjustments&diff=1483Rigging Checks and adjustments2006-01-14T18:13:57Z<p>24.221.130.104: </p>
<hr />
<div>'''Rigging Checks'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench.jpg]]<br />
<br />
'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''<br />
<br />
Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.<br />
<br />
Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.<br />
<br />
The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998-- at the first Cody Convention when I spearheaded the effort to start the rigging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!<br />
<br />
Significant performance changes can be obtained by removing the errors and getting the plane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.<br />
<br />
<br />
'''Rigging Adjustments'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]<br />
<br />
'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''<br />
<br />
After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool I've found), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.<br />
<br />
The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.<br />
<br />
Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel. If the flap motor and drive assembly is moving the flaps too much or too little travel, then its probably a limit switch problem, either adjustment or failure. If the correct amount of travel in total degrees of movement is correct, then the flap drive mechanicsm can be adjusted via the heim joints on each side to place the flap in the correct position at the UP stop. An note on adjusting the flaps, many planes have excessive play in the flaps. This seems especially prevalent on the AA-5 series, which have a more complex flap drive and more places to allow wear and increase the play. This would also be a good time to verify that the aileron torque tube is accurately centered within the flap torque tube. This keeps the pins on the special flap drive bolts from possibly wearing a groove in the aileron torque tube.<br />
<br />
Aileron rigging is subject to several possible faults. The cables can be incorrectly tensioned, the adjustment of the front cables to the control yoke and be miss-ajusted relative to the aft "turn around" cable that connects the 2 cables from the yokes, the aileron outboard bracket can be bent or damaged, and the outboard aileron bracket can be positioned incorrectly on the aft spar.<br />
<br />
Cable tensioning requires a cable tensiometer, which ought to have its calibration checked, if you are unsure of its testing and certification status. The basic operation is to clamp the tensiometer onto the cable in question and read the tension on the scale appropriate for the diameter of the cable. Adjustments are made by removing the safety wire or locking clip that holds the turnbuckle such that it can not let the cables unscrew from its ends. The first thing one needs to know about turnbuckles is that they have RH threads on one end, and LH threads on the other, such that if one holds the cable ends, and rotate the turnbuckle, you will either loosen or tighten the cable tension. It is important that you not turn one cable to change the tension.<br />
<br />
The [http://www.aircraftspruce.com/pdf/catalog/Cat06142.pdf safety clips or the safety wire] are NOT to be reused, so be sure to have some on hand before you start. Additionally you will need to be familiar with the [http://avstop.com/AC/apgeneral/628b.html correct way to safety wire a turnbuckle], and you'd be surprised at the number of A&Ps that can't do it right without looking at the book. The advantage of the [http://www.aerocraftparts.com/ItemForm.aspx?item=MS21256-1&Category=78ec149d-ecef-4c56-8695-2a6e720af22d MS21256] style safety clips is that they are quick and easy to install correctly, and they [http://avstop.com/AC/apgeneral/628a.html can be installed one-handed in a tight spot] where trying to wrap safety wire would be very difficult. I've seen a mix of turnbuckles installed on the fleet. Some have the groove in the threads for the safety clips, and some don't.<br />
<br />
<br />
<To be continued></div>24.221.130.104https://bondline.org/index.php?title=Rigging_Checks_and_adjustments&diff=1481Rigging Checks and adjustments2006-01-14T18:13:25Z<p>24.221.130.104: </p>
<hr />
<div>'''Rigging Checks'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench.jpg]]<br />
<br />
'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''<br />
<br />
Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.<br />
<br />
Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.<br />
<br />
The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998-- at the first Cody Convention when I spearheaded the effort to start the rigging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!<br />
<br />
Significant performance changes can be obtained by removing the errors and getting the plane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.<br />
<br />
<br />
'''Rigging Adjustments'''<br />
<br />
'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]<br />
<br />
'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''<br />
<br />
After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool I've found), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.<br />
<br />
The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.<br />
<br />
Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel. If the flap motor and drive assembly is moving the flaps too much or too little travel, then its probably a limit switch problem, either adjustment or failure. If the correct amount of travel in total degrees of movement is correct, then the flap drive mechanicsm can be adjusted via the heim joints on each side to place the flap in the correct position at the UP stop. An note on adjusting the flaps, many planes have excessive play in the flaps. This seems especially prevalent on the AA-5 series, which have a more complex flap drive and more places to allow wear and increase the play. This would also be a good time to verify that the aileron torque tube is accurately centered within the flap torque tube. This keeps the pins on the special flap drive bolts from possibly wearing a groove in the aileron torques tube.<br />
<br />
Aileron rigging is subject to several possible faults. The cables can be incorrectly tensioned, the adjustment of the front cables to the control yoke and be miss-ajusted relative to the aft "turn around" cable that connects the 2 cables from the yokes, the aileron outboard bracket can be bent or damaged, and the outboard aileron bracket can be positioned incorrectly on the aft spar.<br />
<br />
Cable tensioning requires a cable tensiometer, which ought to have its calibration checked, if you are unsure of its testing and certification status. The basic operation is to clamp the tensiometer onto the cable in question and read the tension on the scale appropriate for the diameter of the cable. Adjustments are made by removing the safety wire or locking clip that holds the turnbuckle such that it can not let the cables unscrew from its ends. The first thing one needs to know about turnbuckles is that they have RH threads on one end, and LH threads on the other, such that if one holds the cable ends, and rotate the turnbuckle, you will either loosen or tighten the cable tension. It is important that you not turn one cable to change the tension.<br />
<br />
The [http://www.aircraftspruce.com/pdf/catalog/Cat06142.pdf safety clips or the safety wire] are NOT to be reused, so be sure to have some on hand before you start. Additionally you will need to be familiar with the [http://avstop.com/AC/apgeneral/628b.html correct way to safety wire a turnbuckle], and you'd be surprised at the number of A&Ps that can't do it right without looking at the book. The advantage of the [http://www.aerocraftparts.com/ItemForm.aspx?item=MS21256-1&Category=78ec149d-ecef-4c56-8695-2a6e720af22d MS21256] style safety clips is that they are quick and easy to install correctly, and they [http://avstop.com/AC/apgeneral/628a.html can be installed one-handed in a tight spot] where trying to wrap safety wire would be very difficult. I've seen a mix of turnbuckles installed on the fleet. Some have the groove in the threads for the safety clips, and some don't.<br />
<br />
<br />
<To be continued></div>24.221.130.104https://bondline.org/index.php?title=Charging_Systems&diff=1479Charging Systems2006-01-14T18:09:42Z<p>24.221.130.104: </p>
<hr />
<div>'''Mechanical Difficulty:'''[[Image:Wrench2.jpg]]<br />
<br />
[Bob Steward writes]<br />
The Basics:<br />
The battery stores power chemically, the alternator converts the engine's rotating motion into electrical energy, the Voltage Regulator controls the alternator's output to keep the battery charged, but not over charged (which results in boiling out its acid).<br />
<br />
Your battery stopped charging during your last flight. You shed loads by turning off unneeded equipment until you arrived at the airport and landed normally. Congrats on handling the inflight portion properly. Now how do you get it repaired?<br />
<br />
You need to find out exactly which part failed. The usual FBO response is to replace the alternator AND the voltage regulator. They don't have to do much troubleshooting and they sell lots of expensive parts. A Field Rep for [http://www.kellyaerospace.com/index.html Kelly Aerospace], one of the largest OH shops for alternators, came to an FAA Safety meeting that I attended. He told us that 8 out of 10 alternators returned to them as cores for OH worked when tested before disassembly. He stated that we as A&P mechanics in the field were NOT doing our job properly, and that we needed to apply better troubleshooting techniques rather than replace so many functional alternators.<br />
<br />
If you have a Volt-Ohm meter, you can save lots of time and money. Inexpensive voltmeters are widely available from such vendors as [http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92020 Harbor Freight] and [http://www.radioshack.com/product/index.jsp?productId=2103534 Radio Shack], often for as little as $10.<br />
<br />
To help you know what wire goes where, schematics for the Tiger/Cheetah are available from Gary Vougt's web site... http://www.aucountry.com/Team_Folder/Technical/Wire_76-77.html and http://www.aucountry.com/Team_Folder/Technical/Wire_78-79.html <br />
<br />
All the troubleshooting described below is done with the engine OFF and the keys in your pocket.<br />
<br />
Open the cowl and locate the voltage regulator. On Grumman American singles its on the passenger side just inboard of the motor mount attach point, directly above the battery. On AA-5x you'll see a connector on the bottom with several wires. Look closely and you'll see that they are marked with letters on the regulator.<br />
<br />
Visually check all of the wires and their crimped fittings. Pull gently on the crimped fittings.. none of them should be loose. After 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Look for breaks in the shielding pigtails.<br />
<br />
Locate the "S" terminal and turn on the Master. Using your VOM, measure the voltage between the S terminal and a good ground such as the battery's negative terminal. The VOM should read close to 12.6 volts on a fully charged battery. In this example, however, your battery is not fully charged after the in-flight failure of the charging system, so a measurement equal to 10 volts or greater is acceptable. If an acceptable voltage is present, then your Master Switch, Master Relay, Alt Field Circuit Breaker and the associated wiring are all working well enough to charge the battery from the alternator. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Locate the "F" terminal and measure the voltage just as you did at the "S" terminal. As before, if the measured voltage is within a couple of volts of the nominal battery voltage, then the regulator is correctly trying to "excite" the alternator field so that the alternator can produce an output. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Reset the VOM to measure resistance instead of voltage. Remove the "F" wire from the regulator and measure between the wire and ground. You should measure less than 10 ohms of resistance, and usually about 5 ohms. If you have significantly higher resistance (say 20 ohms or more) then there are problems with the alternator field or brushes, or possibly the wiring going to the alternator is in bad condition. A reading of less than 5 ohms, would indicate a short in the Field wire or inside the alternator. Otherwise, since you have the appropriate resistance between the "F" wire and ground, you are through checking the easy stuff, and are ready to pull the nose bowl.<br />
<br />
'''Turn OFF the Master at this time.''' We are through with the powered portion of the testing, so turn off the Master switch.<br />
<br />
Right about now you are wishing that you had installed the split nose bowl STC, because without it you have to remove the propeller to gains access to the alternator.<br />
<br />
'''Mechanical Difficulty:''' [[Image:Wrench3.jpg]]<br />
<br />
Up to this point, we were just CHECKING electrical measurements without any actual disassembly of the plane. If you do not have the split nose bowl STC, then this is the point at which you will require A&P supervision to complete the testing, removal and replacement of the alternator, prop, mounting bracket, etc. [http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/AC9BED30F1D032B9852566AB006BC89C?OpenDocument FAR 43 Appendix A paragraph (c)(19)] permits the owner/pilot to remove and install cowlings, if the prop does not have to be removed, without A&P supervision, after demonstrating the ability to do it correctly.<br />
<br />
On Travelers before 75, you can check the wiring by removing the screws on the right-hand lower cowling and letting the cowl side tip out from the firewall and nose bowl just enough to enable you to reach under the front cylinder and touch the wires on the back of the alternator. On 75 Travelers with the "Cheetah nose" and on all Cheetahs and Tigers, you have to remove the nose bowl to continue troubleshooting. That's OK, because you have already narrowed the source of the problem to that area anyway.<br />
<br />
With the nose bowl off, or at least the lower nose off if you have the split nose, now remove the alternator belt from the pulley. Our testing so far has not ruled out a worn, loose, or missing alternator belt, so make certain that the belt is in good condition and properly tensioned. <br />
<br />
Folks tend to underestimate the amount of tension required on this belt. Just recall that the amount of power required to turn the alternator increases as the SQUARE of its output (charging) current! Lycoming's service information was updated a couple years back, and they now suggest setting belt tension by checking to see if the belt will slip before reaching a specified torque. You can check this by putting a socket on the alternator drive pulley nut and setting a torque wrench to 540 in-lb (45 ft-lb), and then holding the prop and trying to turn the alternator (CCW when viewing it from the front) with the torque wrench. The wrench should indicate 540 in-lb BEFORE the pulley slips. The older method mentioned in the Maintenance Manual, no longer favored by Lycoming, was to press in the center of the belt span between the pulleys and measure the deflection. New belts were to have less deflection than those that were worn. Refer to the maintenance manual if you don't have a torque wrench handy.<br />
<br />
If the belt itself is in good condition and is tensioned correctly, the next step is to remove the alternator for inspection. First release the tension on the belt. To do this, cut the safety wire on the bolt holding the alternator to the bracket, then loosen the bolt enough so that you are able to push the alternator up, thus relieving the belt tension.<br />
<br />
In the next step, you remove the alternator, which is quite heavy. If you have a portable service table or stand, now would be a good time to position it under the alternator. Now remove the big bolt at the bottom of the alternator (the one that holds it to the engine mounting bracket). While supporting the alternator so the wiring is not stressed, remove the bolt that was safety wired. The alternator should slide off the engine mounting bracket and be attached only by the wiring on the back. <br />
<br />
Carefully turn the alternator around, and lift the rubber boot that hides the connection of the big wire to the back of the alternator. This is a VERY common failure point on the aging fleet. The wire breaks off the ring lug that is bolted down, and the alternator output is prevented from flowing back to the battery by the broken connection. Look also at the small wire that is bolted to the same connection. This is the "A" or sense wire which tells the Voltage Regulator what the alternator is doing. The sense wire is also a common failure point, though not as often as the larger output wire. Look at the other small wire which attaches to a different post. This is the "F" or field wire. If the resistance checks were normal earlier, then this wire should be fine; nevertheless, after 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Check the sheilding pigtails behind the alternator, they can rub on the baffling and get worn through.<br />
<br />
If there are no obvious failures in the wiring, you need to mark them and remove them so that the alternator can be tested at a shop. Pep-Boys and AutoZone will check your alternator for free. Tell them its from a 71 Ford Pickup with AC. That is the actual original application for the DOFF-10300J alternator on your plane.<br />
<br />
After the alternator is spun up and bench tested, all but the rarest and intermittent failures will have been diagnosed, and you will be repairing JUST the wiring, or replacing the alternator or the voltage regulator, and NOT spending money on needless repairs.<br />
<br />
Prior to installing the alternator, carefully inspect the U shaped mounting bracket for cracks. They are prone to crack across the middle of the U, often into one of the bolt holes. Replacement brackets are available from any Lycoming distributor or from FletchAir.</div>24.221.130.104https://bondline.org/index.php?title=Charging_Systems&diff=1417Charging Systems2006-01-07T18:46:29Z<p>24.221.130.104: </p>
<hr />
<div>'''Mechanical Difficulty:'''[[Image:Wrench2.jpg]]<br />
<br />
[Bob Steward writes]<br />
The Basics:<br />
The battery stores power chemically, the alternator converts the engine's rotating motion into electrical energy, the Voltage Regulator controls the alternator's output to keep the battery charged, but not over charged (which results in boiling out its acid).<br />
<br />
Your battery stopped charging during your last flight. You shed loads by turning off unneeded equipment until you arrived at the airport and landed normally. Congrats on handling the inflight portion properly. Now how do you get it repaired?<br />
<br />
You need to find out exactly which part failed. The usual FBO response is to replace the alternator AND the voltage regulator. They don't have to do much troubleshooting and they sell lots of expensive parts. A Field Rep for [http://www.kellyaerospace.com/index.html Kelly Aerospace], one of the largest OH shops for alternators, came to an FAA Safety meeting that I attended. He told us that 8 out of 10 alternators returned to them as cores for OH worked when tested before disassembly. He stated that we as A&P mechanics in the field were NOT doing our job properly, and that we needed to apply better troubleshooting techniques rather than replace so many functional alternators.<br />
<br />
If you have a Volt-Ohm meter, you can save lots of time and money. Inexpensive voltmeters are widely available from such vendors as [http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92020 Harbor Freight] and [http://www.radioshack.com/product/index.jsp?productId=2103534 Radio Shack], often for as little as $10.<br />
<br />
All the troubleshooting described below is done with the engine OFF and the keys in your pocket.<br />
<br />
Open the cowl and locate the voltage regulator. On Grumman American singles its on the passenger side just inboard of the motor mount attach point, directly above the battery. On AA-5x you'll see a connector on the bottom with several wires. Look closely and you'll see that they are marked with letters on the regulator.<br />
<br />
Visually check all of the wires and their crimped fittings. Pull gently on the crimped fittings.. none of them should be loose. After 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Look for breaks in the shielding pigtails.<br />
<br />
Locate the "S" terminal and turn on the Master. Using your VOM, measure the voltage between the S terminal and a good ground such as the battery's negative terminal. The VOM should read close to 12.6 volts on a fully charged battery. In this example, however, your battery is not fully charged after the in-flight failure of the charging system, so a measurement equal to 10 volts or greater is acceptable. If an acceptable voltage is present, then your Master Switch, Master Relay, Alt Field Circuit Breaker and the associated wiring are all working well enough to charge the battery from the alternator. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Locate the "F" terminal and measure the voltage just as you did at the "S" terminal. As before, if the measured voltage is within a couple of volts of the nominal battery voltage, then the regulator is correctly trying to "excite" the alternator field so that the alternator can produce an output. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Reset the VOM to measure resistance instead of voltage. Remove the "F" wire from the regulator and measure between the wire and ground. You should measure less than 10 ohms of resistance, and usually about 5 ohms. If you have significantly higher resistance (say 20 ohms or more) then there are problems with the alternator field or brushes, or possibly the wiring going to the alternator is in bad condition. A reading of less than 5 ohms, would indicate a short in the Field wire or inside the alternator. Otherwise, since you have the appropriate resistance between the "F" wire and ground, you are through checking the easy stuff, and are ready to pull the nose bowl.<br />
<br />
'''Turn OFF the Master at this time.''' We are through with the powered portion of the testing, so turn off the Master switch.<br />
<br />
Right about now you are wishing that you had installed the split nose bowl STC, because without it you have to remove the propeller to gains access to the alternator.<br />
<br />
'''Mechanical Difficulty:''' [[Image:Wrench3.jpg]]<br />
<br />
Up to this point, we were just CHECKING electrical measurements without any actual disassembly of the plane. If you do not have the split nose bowl STC, then this is the point at which you will require A&P supervision to complete the testing, removal and replacement of the alternator, prop, mounting bracket, etc. [http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/AC9BED30F1D032B9852566AB006BC89C?OpenDocument FAR 43 Appendix A paragraph (c)(19)] permits the owner/pilot to remove and install cowlings, if the prop does not have to be removed, without A&P supervision, after demonstrating the ability to do it correctly.<br />
<br />
On Travelers before 75, you can check the wiring by removing the screws on the right-hand lower cowling and letting the cowl side tip out from the firewall and nose bowl just enough to enable you to reach under the front cylinder and touch the wires on the back of the alternator. On 75 Travelers with the "Cheetah nose" and on all Cheetahs and Tigers, you have to remove the nose bowl to continue troubleshooting. That's OK, because you have already narrowed the source of the problem to that area anyway.<br />
<br />
With the nose bowl off, or at least the lower nose off if you have the split nose, now remove the alternator belt from the pulley. Our testing so far has not ruled out a worn, loose, or missing alternator belt, so make certain that the belt is in good condition and properly tensioned. <br />
<br />
Folks tend to underestimate the amount of tension required on this belt. Just recall that the amount of power required to turn the alternator increases as the SQUARE of its output (charging) current! Lycoming's service information was updated a couple years back, and they now suggest setting belt tension by checking to see if the belt will slip before reaching a specified torque. You can check this by putting a socket on the alternator drive pulley nut and setting a torque wrench to 540 in-lb (45 ft-lb), and then holding the prop and trying to turn the alternator (CCW when viewing it from the front) with the torque wrench. The wrench should indicate 540 in-lb BEFORE the pulley slips. The older method mentioned in the Maintenance Manual, no longer favored by Lycoming, was to press in the center of the belt span between the pulleys and measure the deflection. New belts were to have less deflection than those that were worn. Refer to the maintenance manual if you don't have a torque wrench handy.<br />
<br />
If the belt itself is in good condition and is tensioned correctly, the next step is to remove the alternator for inspection. First release the tension on the belt. To do this, cut the safety wire on the bolt holding the alternator to the bracket, then loosen the bolt enough so that you are able to push the alternator up, thus relieving the belt tension.<br />
<br />
In the next step, you remove the alternator, which is quite heavy. If you have a portable service table or stand, now would be a good time to position it under the alternator. Now remove the big bolt at the bottom of the alternator (the one that holds it to the engine mounting bracket). While supporting the alternator so the wiring is not stressed, remove the bolt that was safety wired. The alternator should slide off the engine mounting bracket and be attached only by the wiring on the back. <br />
<br />
Carefully turn the alternator around, and lift the rubber boot that hides the connection of the big wire to the back of the alternator. This is a VERY common failure point on the aging fleet. The wire breaks off the ring lug that is bolted down, and the alternator output is prevented from flowing back to the battery by the broken connection. Look also at the small wire that is bolted to the same connection. This is the "A" or sense wire which tells the Voltage Regulator what the alternator is doing. The sense wire is also a common failure point, though not as often as the larger output wire. Look at the other small wire which attaches to a different post. This is the "F" or field wire. If the resistance checks were normal earlier, then this wire should be fine; nevertheless, after 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Check the sheilding pigtails behind the alternator, they can rub on the baffling and get worn through.<br />
<br />
If there are no obvious failures in the wiring, you need to mark them and remove them so that the alternator can be tested at a shop. Pep-Boys and AutoZone will check your alternator for free. Tell them its from a 71 Ford Pickup with AC. That is the actual original application for the DOFF-10300J alternator on your plane.<br />
<br />
After the alternator is spun up and bench tested, all but the rarest and intermittent failures will have been diagnosed, and you will be repairing JUST the wiring, or replacing the alternator or the voltage regulator, and NOT spending money on needless repairs.<br />
<br />
Prior to installing the alternator, carefully inspect the U shaped mounting bracket for cracks. They are prone to crack across the middle of the U, often into one of the bolt holes. Replacement brackets are available from any Lycoming distributor or from FletchAir.</div>24.221.130.104https://bondline.org/index.php?title=Charging_Systems&diff=1399Charging Systems2005-12-27T01:53:58Z<p>24.221.130.104: </p>
<hr />
<div>'''Mechanical Difficulty:'''[[Image:Wrench2.jpg]]<br />
<br />
[Bob Steward writes]<br />
The Basics:<br />
The battery stores power chemically, the alternator converts the engine's rotating motion into electrical energy, the Voltage Regulator controls the alternator's output to keep the battery charged, but not over charged (which results in boiling out its acid).<br />
<br />
Your battery stopped charging during your last flight. You shed loads by turning off unneeded equipment until you arrived at the airport and landed normally. Congrats on handling the inflight portion properly. Now how do you get it repaired?<br />
<br />
You need to find out exactly which part failed. The usual FBO response is to replace the alternator AND the voltage regulator. They don't have to do much troubleshooting and they sell lots of expensive parts. A Field Rep for [http://www.kellyaerospace.com/index.html Kelly Aerospace], one of the largest OH shops for alternators, came to an FAA Safety meeting that I attended. He told us that 8 out of 10 alternators returned to them as cores for OH worked when tested before disassembly. He stated that we as A&P mechanics in the field were NOT doing our job properly, and that we needed to apply better troubleshooting techniques rather than replace so many functional alternators.<br />
<br />
If you have a Volt-Ohm meter, you can save lots of time and money. Inexpensive voltmeters are widely available from such vendors as [http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92020 Harbor Freight] and [http://www.radioshack.com/product/index.jsp?productId=2103534 Radio Shack], often for as little as $10.<br />
<br />
All the troubleshooting described below is done with the engine OFF and the keys in your pocket.<br />
<br />
Open the cowl and locate the voltage regulator. On Grumman American singles its on the passenger side just inboard of the motor mount attach point, directly above the battery. On AA-5x you'll see a connector on the bottom with several wires. Look closely and you'll see that they are marked with letters on the regulator.<br />
<br />
Visually check all of the wires and their crimped fittings. Pull gently on the crimped fittings.. none of them should be loose. After 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Look for breaks in the shielding pigtails.<br />
<br />
Locate the "S" terminal and turn on the Master. Using your VOM, measure the voltage between the S terminal and a good ground such as the battery's negative terminal. The VOM should read close to 12.6 volts on a fully charged battery. In this example, however, your battery is not fully charged after the in-flight failure of the charging system, so a measurement equal to 10 volts or greater is acceptable. If an acceptable voltage is present, then your Master Switch, Master Relay, Alt Field Circuit Breaker and the associated wiring are all working well enough to charge the battery from the alternator. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Locate the "F" terminal and measure the voltage just as you did at the "S" terminal. As before, if the measured voltage is within a couple of volts of the nominal battery voltage, then the regulator is correctly trying to "excite" the alternator field so that the alternator can produce an output. Therefore, your problem is elsewhere. Continue on.<br />
<br />
Reset the VOM to measure resistance instead of voltage. Remove the "F" wire from the regulator and measure between the wire and ground. You should measure less than 10 ohms of resistance, and usually about 5 ohms. If you have significantly higher resistance (say 20 ohms or more) then there are problems with the alternator field or brushes, or possibly the wiring going to the alternator is in bad condition. A reading of less than 5 ohms, would indicate a short in the Field wire or inside the alternator. Otherwise, since you have the appropriate resistance between the "F" wire and ground, you are through checking the easy stuff, and are ready to pull the nose bowl.<br />
<br />
'''Turn OFF the Master at this time.''' We are through with the powered portion of the testing, so turn off the Master switch.<br />
<br />
Right about now you are wishing that you had installed the split nose bowl STC, because without it you have to remove the propeller to gains access to the alternator.<br />
<br />
'''Mechanical Difficulty:''' [[Image:Wrench3.jpg]]<br />
<br />
Up to this point, we were just CHECKING electrical measurements without any actual disassembly of the plane. If you do not have the split nose bowl STC, then this is the point at which you will require A&P supervision to complete the testing, removal and replacement of the alternator, prop, mounting bracket, etc. [http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgFAR.nsf/0/AC9BED30F1D032B9852566AB006BC89C?OpenDocument FAR 43 Appendix A paragraph (c)(19)] permits the owner/pilot to remove and install cowlings, if the prop does not have to be removed, without A&P supervision, after demonstrating the ability to do it correctly.<br />
<br />
On Travelers before 75, you can check the wiring by removing the screws on the right-hand lower cowling and letting the cowl side tip out from the firewall and nose bowl just enough to enable you to reach under the front cylinder and touch the wires on the back of the alternator. On 75 Travelers with the "Cheetah nose" and on all Cheetahs and Tigers, you have to remove the nose bowl to continue troubleshooting. That's OK, because you have already narrowed the source of the problem to that area anyway.<br />
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With the nose bowl off, or at least the lower nose off if you have the split nose, now remove the alternator belt from the pulley. Our testing so far has not ruled out a worn, loose, or missing alternator belt, so make certain that the belt is in good condition and properly tensioned. <br />
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Folks tend to underestimate the amount of tension required on this belt. Just recall that the amount of power required to turn the alternator increases as the SQUARE of its output (charging) current! Lycoming's service information was updated a couple years back, and they now suggest setting belt tension by checking to see if the belt will slip before reaching a specified torque. You can check this by putting a socket on the alternator drive pulley nut and setting a torque wrench to 540 in-lb, and then holding the prop and trying to turn the alternator (CCW when viewing it from the front) with the torque wrench. The wrench should indicate 540 in-lb BEFORE the pulley slips. The older method mentioned in the Maintenance Manual, no longer favored by Lycoming, was to press in the center of the belt span between the pulleys and measure the deflection. New belts were to have less deflection than those that were worn. Refer to the maintenance manual if you don't have a torque wrench handy.<br />
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If the belt itself is in good condition and is tensioned correctly, the next step is to remove the alternator for inspection. First release the tension on the belt. To do this, cut the safety wire on the bolt holding the alternator to the bracket, then loosen the bolt enough so that you are able to push the alternator up, thus relieving the belt tension.<br />
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In the next step, you remove the alternator, which is quite heavy. If you have a portable service table or stand, now would be a good time to position it under the alternator. Now remove the big bolt at the bottom of the alternator (the one that holds it to the engine mounting bracket). While supporting the alternator so the wiring is not stressed, remove the bolt that was safety wired. The alternator should slide off the engine mounting bracket and be attached only by the wiring on the back. <br />
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Carefully turn the alternator around, and lift the rubber boot that hides the connection of the big wire to the back of the alternator. This is a VERY common failure point on the aging fleet. The wire breaks off the ring lug that is bolted down, and the alternator output is prevented from flowing back to the battery by the broken connection. Look also at the small wire that is bolted to the same connection. This the "A" or sense wire which tells the Voltage Regulator what the alternator is doing. The sense wire is also a common failure point, though not as often as the larger output wire. Look at the other small wire which attaches to a different post. This is the "F" or field wire. If the resistance checks were normal earlier, then this wire should be fine; nevertheless, after 30+ years in service all these wires warrant close examination. Generally inspect the wires for large cracks in the insulation, or, where appropriate, the shielding. Check the sheilding pigtails behind the alternator, they can rub on the baffling and get worn through.<br />
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If there are no obvious failures in the wiring, you need to mark them and remove them so that the alternator can be tested at a shop. Pep-Boys and AutoZone will check your alternator for free. Tell them its from a 71 Ford Pickup with AC. That is the actual original application for the DOFF-10300J alternator on your plane.<br />
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After the alternator is spun up and bench tested, all but the rarest and intermittent failures will have been diagnosed, and you will be repairing JUST the wiring, or replacing the alternator or the voltage regulator, and NOT spending money on needless repairs.<br />
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Prior to installing the alternator, carefully inspect the U shaped mounting bracket for cracks. They are prone to crack across the middle of the U, often into one of the bolt holes. Replacement brackets are available from any Lycoming distributor or from FletchAir.</div>24.221.130.104https://bondline.org/index.php?title=Talk:Charging_Systems&diff=1322Talk:Charging Systems2005-12-21T13:44:10Z<p>24.221.130.104: </p>
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<div>Bob... I thought the consensus is the the Voltage Regulator is now referred to as an "Alternator Control Unit" or ACU? <br />
Also visually check for broken shields at the alternator - just found one 2 days ago on my Tiger...:^)<br />
You could also add a link to Gary Vougt's schematics http://www.aucountry.com/Team_Folder/Technical/Wire_76-77.html and http://www.aucountry.com/Team_Folder/Technical/Wire_78-79.html<br />
Gil Alexander</div>24.221.130.104https://bondline.org/index.php?title=Talk:Charging_Systems&diff=1321Talk:Charging Systems2005-12-21T13:30:15Z<p>24.221.130.104: </p>
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<div>Bob... I thought the consensus is the the Voltage Regulator is now referred to as an "Alternator Control Unit" or ACU? <br />
Also visually check for broken shields at the alternator - just found one 2 days ago on my Tiger...:^)<br />
Gil Alexander</div>24.221.130.104https://bondline.org/index.php?title=Talk:Charging_Systems&diff=1320Talk:Charging Systems2005-12-21T13:28:41Z<p>24.221.130.104: </p>
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<div>Bob... I thought the consensus is the the Voltage Regulator is now referred to as an "Alternator Control Unit" or ACU? Gil Alexander</div>24.221.130.104https://bondline.org/index.php?title=Talk:Brake_System&diff=1319Talk:Brake System2005-12-21T13:23:43Z<p>24.221.130.104: </p>
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<div>Bob... mention that the gear leg fairing needs to be cut to inspect and/or replace the brake line... Glue used to repair wet suits (buy at your local dive shop) is good to repair the cut made to the gear leg fairing. Gil Alexander</div>24.221.130.104