Pre-Purchase Inspections - Revision history

Bob Steward: Fixed dead link to Lycoming Service Publication SI 1009AR

2013-08-12T17:08:47Z

Fixed dead link to Lycoming Service Publication SI 1009AR

← Older revision		Revision as of 17:08, 12 August 2013
Line 25:		Line 25:
	One must have the "AR(R)OW" paperwork for flight, and one must have an Airworthiness Certificate to determine that the aircraft in question was EVER in a condition to hold US Certification. Many planes were built and shipped overseas without ever having US paperwork, such as the ones that went directly to Canada that often are brought back to the US later. The price, especially considering the current exchange rates, may be very attractive, but one is left to PROVE to the FAA that the plane conforms to its Type Design and is therefore eligible to have an airworthiness certificate issued.		One must have the "AR(R)OW" paperwork for flight, and one must have an Airworthiness Certificate to determine that the aircraft in question was EVER in a condition to hold US Certification. Many planes were built and shipped overseas without ever having US paperwork, such as the ones that went directly to Canada that often are brought back to the US later. The price, especially considering the current exchange rates, may be very attractive, but one is left to PROVE to the FAA that the plane conforms to its Type Design and is therefore eligible to have an airworthiness certificate issued.

	Logs are an important part of the paperwork. It's quite common to see planes for sale with some or all of the logs missing. This is a big red flag for the novice buyer. WHY are the logs missing? It could be that they were truly lost or destroyed. It's possible that the plane was a repossession or ~~transfered~~ in an estate at some time, and the logs were not available to the new owner. Or, a more nefarious possibility, they were intentionally kept back to avoid the documenting of repairs from some unreported accident! Perhaps there were even substandard repairs that included the use of undocumented parts or unapproved repair techniques. Lost logs require an even higher level of due diligence on the part of the inspector and purchaser.		Logs are an important part of the paperwork. It's quite common to see planes for sale with some or all of the logs missing. This is a big red flag for the novice buyer. WHY are the logs missing? It could be that they were truly lost or destroyed. It's possible that the plane was a repossession or transferred in an estate at some time, and the logs were not available to the new owner. Or, a more nefarious possibility, they were intentionally kept back to avoid the documenting of repairs from some unreported accident! Perhaps there were even substandard repairs that included the use of undocumented parts or unapproved repair techniques. Lost logs require an even higher level of due diligence on the part of the inspector and purchaser.


Line 43:		Line 43:
	Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that it's going to reach TBO and even go well beyond.		Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that it's going to reach TBO and even go well beyond.

	Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.com manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming~~.textron~~.com/~~support~~/~~publications~~/~~maintenancePublications~~/~~serviceInstructions~~/~~SI1009AR~~.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)		Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.com manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.com/Portals/0/techpublications/serviceinstructions/SI%201009AV%20%2807-08-2013%29/Recommended%20Time%20Between%20Overhaul%20Periods.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)

	Now, how do you feel about that 30 year old engine with "mid-time"? It's already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.		Now, how do you feel about that 30 year old engine with "mid-time"? It's already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.

Bob Steward: Fixed dead link to Lycoming

2013-08-12T17:03:01Z

Fixed dead link to Lycoming

← Older revision		Revision as of 17:03, 12 August 2013
Line 43:		Line 43:
	Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that it's going to reach TBO and even go well beyond.		Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that it's going to reach TBO and even go well beyond.

	Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming~~.textron~~.com~~/main.jsp~~ manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)		Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.com manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)

	Now, how do you feel about that 30 year old engine with "mid-time"? It's already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.		Now, how do you feel about that 30 year old engine with "mid-time"? It's already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.

WikiSysop at 12:23, 21 June 2007

2007-06-21T12:23:27Z

← Older revision		Revision as of 12:23, 21 June 2007
Line 37:		Line 37:
	The single largest issue can probably be summed up in one word: '''Corrosion'''. As the fleet ages and time takes its toll on our light alloy airframes, oxidation is the number one problem that the fleet faces. The factory engineers never expected that we'd be flying significant portions of the fleet 35 years after production. They built the planes to last 10-15 years, and then expected that we'd scrap them and buy new ones. If aviation products didn't go up at over twice the rate of inflation, perhaps that would be the case. A new $30,000 Tiger? Sure, where do we mail the check?		The single largest issue can probably be summed up in one word: '''Corrosion'''. As the fleet ages and time takes its toll on our light alloy airframes, oxidation is the number one problem that the fleet faces. The factory engineers never expected that we'd be flying significant portions of the fleet 35 years after production. They built the planes to last 10-15 years, and then expected that we'd scrap them and buy new ones. If aviation products didn't go up at over twice the rate of inflation, perhaps that would be the case. A new $30,000 Tiger? Sure, where do we mail the check?

	Recently there seems to be a rash of planes with corrosion in the center spar. Not some light surface corrosion that might leave little pits in the spar tube, but full blown inter-granular corrosion that was raising bumps on the spar tube. This requires an expensive center spar and many hours of labor to replace it. Not all planes that have this sort of corrosion are "Florida" planes. The corrosion is severe enough on many planes that you have to ask WHEN in the last 20 years of annual inspections was this overlooked, since it was quite obvious that it hadn't JUST popped up in the last few months.		Recently there seems to be a rash of planes with corrosion in the center spar. Not some light surface corrosion that might leave little pits in the spar tube, but full blown inter-granular corrosion that was raising bumps on the spar tube. This requires an expensive center spar and many hours of labor to replace it. Not all planes that have this sort of corrosion are "Florida" planes. The corrosion is severe enough on many planes that you have to ask WHEN in the last 20+ years of annual inspections was this overlooked, since it was quite obvious that it hadn't JUST popped up in the last few months.

	'''Engine'''		'''Engine'''

GhyT1q at 21:34, 20 June 2007

2007-06-20T21:34:16Z

← Older revision		Revision as of 21:34, 20 June 2007
Line 37:		Line 37:
	The single largest issue can probably be summed up in one word: '''Corrosion'''. As the fleet ages and time takes its toll on our light alloy airframes, oxidation is the number one problem that the fleet faces. The factory engineers never expected that we'd be flying significant portions of the fleet 35 years after production. They built the planes to last 10-15 years, and then expected that we'd scrap them and buy new ones. If aviation products didn't go up at over twice the rate of inflation, perhaps that would be the case. A new $30,000 Tiger? Sure, where do we mail the check?		The single largest issue can probably be summed up in one word: '''Corrosion'''. As the fleet ages and time takes its toll on our light alloy airframes, oxidation is the number one problem that the fleet faces. The factory engineers never expected that we'd be flying significant portions of the fleet 35 years after production. They built the planes to last 10-15 years, and then expected that we'd scrap them and buy new ones. If aviation products didn't go up at over twice the rate of inflation, perhaps that would be the case. A new $30,000 Tiger? Sure, where do we mail the check?

	Recently there seems to be a rash of planes with corrosion in the center spar. Not some light surface corrosion that might leave little pits in the spar tube, but full blown inter-granular corrosion that was raising bumps on the spar tube. This requires an expensive center spar and many hours of labor to replace it. Not all planes that have this sort of corrosion are "Florida" planes. The corrosion is severe enough on many planes that you have to ask WHEN in the last 20+ years of annual inspections was this overlooked, since it was quite obvious that it hadn't JUST popped up in the last few months.		Recently there seems to be a rash of planes with corrosion in the center spar. Not some light surface corrosion that might leave little pits in the spar tube, but full blown inter-granular corrosion that was raising bumps on the spar tube. This requires an expensive center spar and many hours of labor to replace it. Not all planes that have this sort of corrosion are "Florida" planes. The corrosion is severe enough on many planes that you have to ask WHEN in the last 20 years of annual inspections was this overlooked, since it was quite obvious that it hadn't JUST popped up in the last few months.

	'''Engine'''		'''Engine'''

Bob Steward: spelling correction

2006-09-15T22:52:39Z

spelling correction

← Older revision		Revision as of 22:52, 15 September 2006
Line 25:		Line 25:
	One must have the "AR(R)OW" paperwork for flight, and one must have an Airworthiness Certificate to determine that the aircraft in question was EVER in a condition to hold US Certification. Many planes were built and shipped overseas without ever having US paperwork, such as the ones that went directly to Canada that often are brought back to the US later. The price, especially considering the current exchange rates, may be very attractive, but one is left to PROVE to the FAA that the plane conforms to its Type Design and is therefore eligible to have an airworthiness certificate issued.		One must have the "AR(R)OW" paperwork for flight, and one must have an Airworthiness Certificate to determine that the aircraft in question was EVER in a condition to hold US Certification. Many planes were built and shipped overseas without ever having US paperwork, such as the ones that went directly to Canada that often are brought back to the US later. The price, especially considering the current exchange rates, may be very attractive, but one is left to PROVE to the FAA that the plane conforms to its Type Design and is therefore eligible to have an airworthiness certificate issued.

	Logs are an important part of the paperwork. It's quite common to see planes for sale with some or all of the logs missing. This is a big red flag for the novice buyer. WHY are the logs missing? It could be that they were truly lost or destroyed. ~~Its~~ possible that the plane was a repossession or transfered in an estate at some time, and the logs were not available to the new owner. Or, a more nefarious possibility, they were intentionally kept back to avoid the documenting of repairs from some unreported accident! Perhaps there were even substandard repairs that included the use of undocumented parts or unapproved repair techniques. Lost logs require an even higher level of due diligence on the part of the inspector and purchaser.		Logs are an important part of the paperwork. It's quite common to see planes for sale with some or all of the logs missing. This is a big red flag for the novice buyer. WHY are the logs missing? It could be that they were truly lost or destroyed. It's possible that the plane was a repossession or transfered in an estate at some time, and the logs were not available to the new owner. Or, a more nefarious possibility, they were intentionally kept back to avoid the documenting of repairs from some unreported accident! Perhaps there were even substandard repairs that included the use of undocumented parts or unapproved repair techniques. Lost logs require an even higher level of due diligence on the part of the inspector and purchaser.


Line 45:		Line 45:
	Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)		Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)

	Now, how do you feel about that 30 year old engine with "mid-time"? ~~Its~~ already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.		Now, how do you feel about that 30 year old engine with "mid-time"? It's already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.

	===The Inspection Process===		===The Inspection Process===

Bob Steward: spelling correction

2006-09-15T22:50:41Z

spelling correction

← Older revision		Revision as of 22:50, 15 September 2006
Line 41:		Line 41:
	'''Engine'''		'''Engine'''

	Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that ~~its~~ going to reach TBO and even go well beyond.		Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that it's going to reach TBO and even go well beyond.

	Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)		Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)

	Now, how do you feel about that 30 year old engine with "mid-time"? Its already 250% past ~~its~~ factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.		Now, how do you feel about that 30 year old engine with "mid-time"? Its already 250% past it's factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.

	===The Inspection Process===		===The Inspection Process===
Line 53:		Line 53:
	At this point, the price has been agreed to, the buyer wants to purchase the plane, and the seller is willing to sell and warrant the plane to be as represented.		At this point, the price has been agreed to, the buyer wants to purchase the plane, and the seller is willing to sell and warrant the plane to be as represented.

	The Pre-Purchase Inspection is now scheduled, with the intent of determining if the plane meets the stated condition by the seller. The purpose is not to pick the airplane to pieces and scare away the buyer or to find thousands of dollars worth of work the seller should pay for, rather it is to establish the true condition of the plane for comparison with the previously prepared squawk list. ~~Its~~ possible (and desireable) to do a PPI on a WRECKED plane. Again, the purpose is to bring to light the true condition of the plane, so that both parties are aware and accept the current condition as the basis for the sale.		The Pre-Purchase Inspection is now scheduled, with the intent of determining if the plane meets the stated condition by the seller. The purpose is not to pick the airplane to pieces and scare away the buyer or to find thousands of dollars worth of work the seller should pay for, rather it is to establish the true condition of the plane for comparison with the previously prepared squawk list. It's possible (and desireable) to do a PPI on a WRECKED plane. Again, the purpose is to bring to light the true condition of the plane, so that both parties are aware and accept the current condition as the basis for the sale.

	It's quite common to surprise the owner with items that are worn, cracked, corroded, etc. And the seller and buyer make adjustments in the price to account for them, or the seller has them repaired to everyone's satisfaction, in order to bring the plane back to the previously stated condition, upon which the sale price was negotiated.		It's quite common to surprise the owner with items that are worn, cracked, corroded, etc. And the seller and buyer make adjustments in the price to account for them, or the seller has them repaired to everyone's satisfaction, in order to bring the plane back to the previously stated condition, upon which the sale price was negotiated.

Bob Steward: spelling correction

2006-09-15T22:46:49Z

spelling correction

← Older revision		Revision as of 22:46, 15 September 2006
Line 11:		Line 11:
	Most planes sell because the owner is moving on. Sometimes it's to larger or smaller aircraft, but often it's away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.		Most planes sell because the owner is moving on. Sometimes it's to larger or smaller aircraft, but often it's away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.

	Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while ~~its~~ true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.		Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while it's true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.

	So if ~~its~~ just been inspected, and no actual work was done to repair or improve the plane, just what did you get? Probably just bare minimum that the FAA requires for the plane to be legally operated. Certainly nothing that says there won't be any catastrophic failures or even minor items wearing or breaking on the very next flight. The plane was just "looked at". Maybe sort of a super pre-flight.		So if it's just been inspected, and no actual work was done to repair or improve the plane, just what did you get? Probably just bare minimum that the FAA requires for the plane to be legally operated. Certainly nothing that says there won't be any catastrophic failures or even minor items wearing or breaking on the very next flight. The plane was just "looked at". Maybe sort of a super pre-flight.

	There have been many tales on the GG of woe and expense after purchasing a plane, and yet it seems that new buyers never learn, and the same mistakes are repeated again and again.		There have been many tales on the GG of woe and expense after purchasing a plane, and yet it seems that new buyers never learn, and the same mistakes are repeated again and again.

Bob Steward: spelling correction

2006-09-15T22:45:13Z

spelling correction

← Older revision		Revision as of 22:45, 15 September 2006
Line 9:		Line 9:
	Perhaps, but who did the inspection, and did you get a copy of the signed, dated list of discrepancies?		Perhaps, but who did the inspection, and did you get a copy of the signed, dated list of discrepancies?

	Most planes sell because the owner is moving on. Sometimes it's to larger or smaller aircraft, but often ~~its~~ away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.		Most planes sell because the owner is moving on. Sometimes it's to larger or smaller aircraft, but often it's away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.

	Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while its true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.		Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while its true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.

Bob Steward: spelling correction

2006-09-15T22:44:28Z

spelling correction

← Older revision		Revision as of 22:44, 15 September 2006
Line 9:		Line 9:
	Perhaps, but who did the inspection, and did you get a copy of the signed, dated list of discrepancies?		Perhaps, but who did the inspection, and did you get a copy of the signed, dated list of discrepancies?

	Most planes sell because the owner is moving on. Sometimes ~~its~~ to larger or smaller aircraft, but often its away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.		Most planes sell because the owner is moving on. Sometimes it's to larger or smaller aircraft, but often its away from aviation. So what did they tell the mechanic that performed the last annual? Probably something along the lines of: "I've got it listed in T-A-P, so don't spend any money on it that you don't have to." That is a pretty sobering thought when you know that you are going to take your family and friends up in your new plane just as soon as you can get it home.

	Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while its true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.		Another factor that enters the discussion is that an "Annual Inspection" is just that, INSPECTION. As in LOOK at it. No repairs or service work are part of the inspection. And while its true that the basic oil, filter, fluid levels and mag timing checks are regularly performed inconjunction with the inspection, that is just a convenience for the owner, since the plane is in the shop, they have it opened up, and most planes haven't had any service work since LAST year.

Bob Steward: Added link to VWT

2006-09-01T15:38:28Z

Added link to VWT

← Older revision		Revision as of 15:38, 1 September 2006
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	Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that its going to reach TBO and even go well beyond.		Sellers are very fond of speaking highly of the good running of the engine, even though it's at or very near TBO. The implication, if not outright spoken statement is that TBO is just a "suggestion" and since THIS engine is running so well, has such fine compression and uses negligible oil between changes, that its going to reach TBO and even go well beyond.

	Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the SB388C "Valve Wobble" test to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)		Of course this is total hog wash. No one can predict the future accurately by relying solely on past events. There are inspections such as the [http://www.bondline.org/index.php/Valve_Wobble_Testing SB388C "Valve Wobble" test] to check for hidden wear, and even invasive inspections like pulling cylinders to look at the cam and tappet bodies for spalling and corrosion to help determine if the engine is healthy. The [http://www.lycoming.textron.com/main.jsp manufacturer (Lycoming)] has established a TBO based on field experience. What Lycoming has actually said is the criteria for determining what the REAL TBO for a particular engine should be is in [http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1009AR.pdf Lycoming SI 1009AR], and is based on 12 calendar years, OR 2000 hours, WHICH EVER COMES FIRST. (Or 2400 for O-235C and O-235L series in the AA-1x, under certain restrictions.)

	Now, how do you feel about that 30 year old engine with "mid-time"? Its already 250% past its factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.		Now, how do you feel about that 30 year old engine with "mid-time"? Its already 250% past its factory recomended TBO! Busting the TBO by a few percent is one thing, by 2-1/2 times is another.