Pre-Purchase Inspections

Mechanical Difficulty: (Not that you'd do your own inspection...)

[Bob Steward writes] There are as many different ideas on the proper scope and depth of a pre-purchase inspection as there are buyers. What makes that interesting is the expectations of those buyers, and how those expectations change after owning a plane for 11 months and having gone through the dreaded "first annual".

When is it a better time to discover the true condition of the plane, during the purchase process or after the money has changed hands and the plane has flown away? This is the reason I always suggest that a purchaser do a thorough pre-buy and do all that is reasonable to identify things that will later bite him in the wallet. What that means is a full annual inspection by the check list in the factory maintenance manual -- 13 pages for the AA-5x, a few less for the AA-1x.

"But it just had a fresh annual last month and has flown nearly no hours since then."

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.

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.

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.

I've read so 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.

Lets go over some items that really ought to be checked during the pre-buy inspection on your intended purchase.

Paperwork

As strange as it may seem, the FAA is more focused on the paperwork than they are on the actual components. The reason for this is that if the paperwork is correct, then the physical components can be manipulated to create "Airworthiness". However if the paperwork is incorrect, then one can not make the plane "Airworthy" because the records that support the airworthiness are incomplete or inaccurate.

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. Its 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 substandard repairs that included the use of undocumented parts or unapproved repair techniques.

Prop

Props have a TBO, just like engines. When is it due for an OH? Just consult the manufacturer's data for the prop in question. Most fixed pitch props are due for OH at engine OH, or at any time that they have wear or damage that exceeds the prop manufacturer's field dressing limits. Props are a "Class 1" appliance in FAA speak, and that means that they SHOULD have their own log.

Airframe

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 I mail the check?

Engine

Sellers are very fond of speaking highly of the good running of the engine, even though its 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. Noone can predict the future accurately by relying only on past events. The 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 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.

<To be continued>