What a pre-buy inspection should cover — and who should do it

A pre-buy inspection is the one step in an aircraft purchase that can save you more than it costs, and most first-time buyers get it wrong in the same two ways: they let the wrong shop do it, and they let it happen in the wrong place. I know, because I did both.

When I bought my first airplane, the logbooks showed a clean run of annuals. What they didn’t show was that those were paper annuals: signed off to satisfy the FAA, not to reflect the actual condition of the aircraft. The pre-buy happened at a shop that had never seen the type, close to the seller, and it found what a general once-over finds. The real list came later, on my dime.

Here is what a pre-buy should actually cover.

A pre-buy is not an annual

An annual inspection is a regulatory event. An IA signs that the aircraft meets its type design and is in a condition for safe operation on that day. A pre-buy inspection has no regulatory definition at all. Its scope is whatever you and the shop agree on, which means the burden is on you to define it.

That cuts both ways. A seller offering a “fresh annual” instead of a pre-buy is offering you an inspection whose scope you didn’t set, done by a shop you didn’t choose. Take the annual as a data point, not as the inspection.

Who should perform it

Three rules:

1. A shop that knows the type. Every airframe has its known weak points. A Bonanza shop knows where to look for wing-bolt corrosion and ruddervator issues; a Cirrus shop knows parachute repack dates and the questions to ask about the airframe life limit. A generalist will miss what a specialist checks on reflex.
2. A shop with no relationship to the seller. Not the seller’s mechanic, not the shop on the seller’s field, not the shop the seller recommends. The person inspecting the aircraft should be working for you and only you.
3. A shop you’ve briefed. Send the logbooks ahead of time, tell them what the aircraft is for, and tell them what would make you walk. A pre-buy that starts with the mechanic reading the logs at the hangar door is already behind.

If that means flying the aircraft to a shop two states away, that is usually money well spent. The cost of a ferry flight is small next to the cost of what a weak inspection misses.

What the inspection should include

Scope varies by type and price, but a serious pre-buy on a piston single or light twin should cover:

• Logbook review first. Airframe, engine and propeller logs, the AD compliance list, 337 forms, and any damage history. Gaps, missing logs and inconsistent entries are findings in their own right. (See How to read aircraft logbooks before you buy.)
• Engine. Compression check, borescope of each cylinder, oil filter and screen inspection, a look at the oil analysis trend if the owner has one, and an inspection of the exhaust, baffles, hoses and mounts. Cylinder numbers alone tell you little; the borescope tells you what is happening inside.
• Airframe and corrosion. Panels opened, not just looked at. Wing attach points, spar carry-through, control surfaces, landing gear and the belly. Where the aircraft has lived matters: an airplane tied down near salt water gets a harder look than one hangared in the desert.
• Control and gear systems. Cable tension, control travel, retractable gear swing on jacks, bushings and rod ends. Gear problems are expensive and easy to hide on a walk-around.
• Avionics and electrical. Everything turned on and tested, not just the panel glanced at. Pitot-static and transponder certification dates. Wiring behind the panel, especially where equipment has been added over the years.
• Fuel system. Tanks or bladders, sumps, selector valve, and evidence of leaks or staining.
• A test flight, ideally with the inspecting mechanic aboard or at least with the results reported to them.

On a turboprop, add the engine trend data, hot-section status and program paperwork to that list; see light twins and turboprops.

Ask for a written report with photos. A good shop will produce one without being asked; it is the document you negotiate from.

What to do with the findings

No used aircraft comes back clean. The point of the pre-buy is not to find a perfect airplane; it is to know what you are buying and price it accordingly. Sort the findings into three piles: airworthiness items the seller fixes before closing, deferred items that come off the price, and cosmetic items you accept. Then negotiate from the written report, not from memory.

If the findings change your mind about the aircraft entirely, walk away. That is the inspection doing its job.

Where a broker fits

A buyer’s representative does three things here: picks the shop, sets the scope, and turns the findings into a negotiating position. That is the part I didn’t have when I bought my first airplane, and it is the part I now provide. Buyer representation covers the search, the pre-buy and the closing; if you’d rather talk it through first, get in touch and tell me what you’re looking for.