What to look for in aircraft logbooks before buying

A used airplane is only as good as the records that come with it. The paint, the panel, the fresh interior — all of it can be redone in a weekend. The maintenance history can't. Here's how I read a set of logbooks when a buyer asks me to look before they sign.

I'm an FAA Airframe & Powerplant mechanic with Inspection Authorization, and I own and fly my own airplane. When I review logbooks for a buyer, I'm reading them the same way I'd read them if I were about to put my own signature on the aircraft's return to service. That's the standard that matters — not "does it look nice," but "does the paperwork prove this airplane is what the seller says it is."

Start with the big three: airframe, engine, and propeller

Every aircraft should have separate, continuous records for the airframe, the engine (each engine, on a twin), and the propeller. The first thing I check is whether all of them are present and whether they tell one consistent story. Times should line up. Dates shouldn't contradict each other. If the airframe log shows the airplane flying in a year the engine log says it was in pieces on a bench, something's wrong — and it's my job to find out what.

Damage history: the thing that follows an airplane forever

This is where the real money is won or lost. A prop strike, a gear-up landing, a hard landing, or major structural or corrosion repair doesn't just cost money to fix once — it permanently affects the aircraft's value and can raise questions with every future buyer, lender, and insurer.

Damage isn't always announced in plain language. Sometimes it shows up as a major repair on an FAA Form 337, sometimes as an engine teardown "for cause," sometimes as a suspicious cluster of work all dated within a few days. Part of reading logbooks well is recognizing the fingerprints of an event even when nobody wrote "prop strike" in the margin.

Airworthiness Directives (ADs): is the airplane legal to fly?

Airworthiness Directives are mandatory. An aircraft with an uncomplied-with applicable AD is, by definition, not airworthy until it's addressed. I check whether applicable ADs have been complied with, whether recurring ADs are being tracked with a clear next-due, and whether the method of compliance is actually documented rather than just assumed. An airplane with sloppy AD tracking isn't necessarily a bad airplane — but it's a bill and a paperwork project waiting for the next owner.

Continuity and gaps: what's missing matters as much as what's there

Missing logbooks are one of the most underrated value-killers in general aviation. If a chunk of the airplane's life is undocumented, you can't prove what happened during that time — and "we can't prove it" reads, to a careful buyer, the same as "something might be hidden." I look for unexplained time jumps, missing books, and whether major events (like an overhaul) are actually documented or just claimed.

Engine status: SMOH is not the whole story

Buyers love a low "SMOH" number (time since major overhaul), but the number alone doesn't tell you much. I want to know what kind of overhaul it was (factory reman vs. overhaul vs. field overhaul), who did it, whether it was done to service limits or new limits, and — critically — how the engine has been used since. An engine that's flown regularly is usually healthier than one that sat for years with 200 "low" hours on it.

Inspection and annual history

I check the current annual status and the pattern of inspections over time. Consistent annuals with squawks that got addressed tell one story; a gap in annuals, or the same squawk reappearing year after year, tells another. I also confirm the required recurring inspections — pitot-static, transponder, ELT — are current where applicable.

The bottom line

Reading logbooks well is pattern recognition built on years of actually doing the work. A buyer reading their first set of logs sees dates and signatures. A mechanic sees a story — and notices when part of the story is missing. Before you spend money traveling for a physical pre-buy, or worse, before you wire funds, it's worth having someone read that story who's written thousands of those entries themselves.