Caveat emptor, caveat vendor


April 2004


Recently, one of my customers put his airplane up for sale. The potential buyer’s mechanic of choice did a pre-purchase inspection and produced a list of discrepancies. The squawk list from that inspection led to much discussion and was the inspiration for this month’s Shop Talk. What can the seller and buyer expect from the pre-purchase inspection and what is the importance of each of the items on the squawk list? We will also discuss what both parties should and should not do. Some things will seem to be common sense, but sometimes common sense is not so common.


As the buyer, once you have located the airplane that you want, contact the owner or broker. First, verify that all the advertised numbers and avionics equipment are correct. Many ads may be a little misleading, although probably not intentionally so. Next, get a photocopy of the airframe and engine logbooks, all the way back to day one. If you can’t get these photocopies for any reason, just move on to the next airplane. A real seller will supply the documentation that you need to be a real buyer. Do not put a deposit on an airplane with a hidden past. Take the photocopies ASAP to your favorite mechanic for a review and interpretation. Get this done quickly as this airplane is still for sale. Another buyer might purchase it before you can. Confirm the latest tachometer time for the airplane; ask if it is being flown and how much. The ad may be several weeks old and you need to determine the current state of the aircraft.


Never do a logbook review or pre-buy inspection with the mechanic that regularly works on this aircraft. If any questions arise about the maintenance history, talk to the mechanic and get his view on it, but always get a second opinion from a neutral party regarding the general condition of the aircraft. With that in mind, it is a good idea to not have the shop that will be maintaining the aircraft do the inspection. While the mechanic is reviewing the logbooks, make a list of interesting items and events in this airplane’s history and have a title and lien search performed. Remember that you still have no deposit on the aircraft, so the owner or sales agent can sell it out from under you; time is of the essence here.


So the airplane logs and title are okay, what’s next? Arrange for the pre-buy inspection. If the plane is more that a two-hour flight away (in that airplane, not an airline), arrange for an inspection near the airplane’s base of operation. The sales agent or owner will push you for a deposit and now is the time to commit. The seller will want as much money as possible and buyer will want as little as possible. What’s a good amount? There is no set precedent here, but I think that 5 to 10 % of the purchase price fully refundable less the cost of transporting the airplane to the pre-buy inspection and back home is adequate to show the seller you are a serious buyer. Get an agreement on the transportation cost prior to moving the aircraft.

At this point in the process, the seller should have photocopies of the logbooks and a few phone calls invested into the sale. If the buyer wants the seller to fly the aircraft for a pre-purchase inspection to a different location than the aircraft base then realize that the cost of relocating the aircraft for the buyer’s benefit will cost the buyer not the seller. If the buyer makes the aircraft relocation job easy then the seller would be more apt to facilitate the buyer. Get the pre-purchase inspection done close to the airplane’s location. If the aircraft is to be flown, the buyer should make every effort to be on the trip. It is an excellent opportunity to begin the familiarization process. An in-flight survey of controls, rigging, instruments and avionics can be accomplished and being present at the inspection is important. Clearly, careful scheduling can make this part go easier.


We now have a deposit on the aircraft and it is in the hands of a neutral mechanic for a pre-buy inspection. The buyer has the history from the logbook review and the seller has arrived with aircraft logbooks and FAA documents for everyone to verify. The seller should never release the logbooks to anyone except the pre-buy mechanic. The complete set of logbooks is a major portion of an aircraft’s value.


The seller also should try to stay with the airplane while the mechanic is doing the pre-buy inspection. When questions come up the seller is there to answer them as best as possible and preserve the sale price. If the buyer’s mechanic says that they only do annuals and not pre-buys, then find another mechanic. In this case, if the buyer insists on this mechanic for the pre-buy, find another buyer.



As the seller or buyer, do not get talked into expensive repairs that may not be necessary at this time. Both parties should get a copy of the pre-buy list. The airplane propeller and engine history should indicate the total time since new and total time since overhaul. Any damage history should also record the date and tachometer time of occurrence. Repetitive airworthiness directives and time life components should be listed along with their service or replacement time. The following discrepancy list is a reprint from an actual pre-buy inspection. We will divide the list into four categories, airworthy items, expensive items, preventive maintenance items (normal wear & minor fixes) and cosmetic items.

  1. Nose steering horn needs shimming.

  2. Several bolts loose in landing gear system.

  3. Left brake leaking.

  4. Minor corrosion in areas of the aircraft.

  5. Heat shrink is loose on the middle stabilizer trim tube.

  6. Left side kick-panel is cracked and broken.

  7. Armrest on pilot’s seat is broken.

  8. Back spring clutch due replacement at 1961.4 hours.

  9. Mooney Service Bulletin m20-279 not complied with.

  10. Interior trim panel above door broken.

  11. Both flaps chaffing hard on bottom of both wings.

  12. #4 cylinder tube cracked approx. one-third of the flange.

  13. Hardware missing on de-ice brush block.

  14. Oil leak at #1 alternator.

  15. Oil leak at oil pressure relief valve.

  16. Alternate door scat hose not square type.

  17. Turn coordinator not working properly. Airplane loose and sensitive.

  18. Oil in induction system between turbo and intercooler (check valves?)

  19. Rivets loose on cowling duct for exhaust pipe area.

  20. Spinner loose, needs shimming on prop dome.

  21. Duct worn induction air box (rubber duct)

  22. Intercooler flange cracked on forward side.

  23. Prop de-ice wiring chaffing on top of intercooler.

  24. Bolt loose for prop & mixture control cables at the governor & fuel pump.

  25. Rubber baffle seal is old and hard, not sealing in all areas.

  26. Aluminum baffling cracked in several places. Needs to seal at engine (big gaps).

  27. Scratches on inside of windshield.

  28. No markings on compass card.

  29. Glare shield cracked and broken in middle.

  30. Wing walk material coming up in many places.

  31. Static wick broken on left elevator.

  32. Paint coming off on numerous rivets.

  33. Two small dents on right wing, one on leading edge on top.

  34. Light hail damage to top of ailerons, elevators, a few spots on wing.

After looking at this list, realize that if the aircraft is operated under FAR 91 rules, compliance with service bulletins and service letters is not required. Some bulletins are important in the fact that they alert mechanics to potential problems occurring on that type of airplane. Do I recommend doing bulletins and letters? Sometimes. The unfortunate situation is the practice of service letters and bulletins being written to cover the manufacturer from liability. Even worse, some manufacturers use service bulletins to render older products economically obsolete to generate new unit sales. Twenty years ago, engineers wrote service bulletins and service letters, now lawyers and marketing departments write them. Items 8 & 9 are from service bulletins. In my opinion, as long as these systems work properly, the only reason to change these parts is if they are high-time; 3000 hrs or more on the airframe. Here are my thoughts on the items listed above:

  1. Does the nose wheel shimmy? If not, then recheck this item at the next annual.

  2. This statement is poorly worded but is easily resolved. Have the mechanic show both seller and buyer the bolts.

  3. How bad is the leak? This could be just an old o-ring, remember this is a used twenty year-old vehicle.

  4. Another poorly worded statement, determine and record the specific spots. All or most will be cosmetic.

  5. This needs re-gluing at the next annual, not a big deal.

  6. Again, at twenty years old, this is a cosmetic item.

  7. Another cosmetic item.

  8. Not required (Part 91), just recommended.

  9. Again, Part 91. What does the bulletin refer to?

  10. A cosmetic item as long as the door closes properly and no placards are missing.

  11. If you adjust the flaps lower, the airplane will not be as fast. If the flap rigging is correct, measure the degree of chaffing and check it again at the next annual.

  12. This is a good find and will need to be replaced as soon as possible, it’s safe for flight, but won’t pass an annual inspection. It will need to be fixed.

  13. Statement needs to be more specific. If the de-ice block is secure and the wiring is secure and working, what’s missing?

  14. Replace the gasket at the next annual. There is no oil pressure at this location. This is a nuisance oil leak.

  15. If this is an external leak(can you see any oil leaking?), fix it as soon as possible. Unfortunately, the squawk is not worded so one can tell. It is probably not serious as there is ample oil pressure at the site. The airplane was just flown and wasn’t covered in oil. Clean the area well and run the engine; then decide.

  16. Parts books are not FAA/PMA approved and you are not required to use only the part listed in the case of Aero Duct. I recall, a couple of years ago that the square duct could not be purchased do to availability, round duct is okay for this installation, if it is double wall you must use double wall duct.

  17. Did the buyer fly in on the airplane? This should already be on the list from the in-flight survey. Otherwise, ask the pilot who just flew the airplane in. He/she should know better than any mechanic how well the turn coordinator works.

  18. A small amount of oil is not uncommon in a turbo-charged aircraft. During engine shutdown, oil is naturally trapped between the check valve and turbo-charger.

  19. Probably just cosmetic, old age. Repair at the next annual.

  20. If the spinner is loose, remove it, inspect for cracks and reshim it. Should take less than 30 minutes.

  21. Is the duct serviceable or worn through? Remember, this is a used vehicle.

  22. Stop drill the crack at the next annual.

  23. Re-secure this at the next annual.

  24. These bolts should rotate, as they are cotter-keyed.

  25. Close the gaps up using PRC at the next annual.

  26. Stop drill the cracks, repair baffling at next annual. Old age.

  27. It’s a used vehicle.

  28. If the deviation is zero at all compass points, then, technically, no markings are required (except Radio On or Off). However, to know that the compass has been swung and the deviation is zero, a logbook entry must be confirmed. Otherwise, swing the compass and record the deviation (put it on the card this time).

  29. Used vehicle.

  30. Used vehicle.

  31. Cosmetic item.

  32. Cosmetic item.

  33. Not an airworthy item (no crushed rib or spar), but potentially expensive to make like new.

  34. Same as 33).

So, what are the airworthiness items on this list? Item 12 and maybe 28. Possible expensive items? 12, 17, 33 and 34. Normal wear & minor repairs? 1-5, 8, 9, 11, 13-16, 20-23, 25, 26, (28). Cosmetic items? The rest. The pre-buy mechanic did his job by listing every thing he saw, and it’s now up to the buyer and seller to interpret how important and expensive each item is.


Final thoughts: If you’re a buyer and this list scares you, then you need to go buy a factory-new airplane. If you’re the seller, don’t be worried over a bunch of cosmetic items; just be prepared to lower your price commensurate with the appearance of your airplane. All buyers, as they walk up to the airplane, see the paint job first. As they crawl inside the plane, the instrument panel and radio panel second. The price is third. If the airplane is not rating an 8 or better on the first two of these items, then plan to readjust number three. Unfortunately, appearances are everything when selling an airplane. One more thought: The buyer or a representative really should fly the airplane. That is the only way to formulate a complete discrepancy list.


As always, if you have a question about this article, you may contact me at my aircraft repair shop, 307-789-6866 or via e-mail. Until the next ShopTalk, enjoy flying your Mooney.