Not every problem in a set of logbooks is a deal-killer. But some are — and a few more should at least stop you cold until you get a straight answer. Here are the seven that make me tell a buyer to slow down.
I'm an A&P/IA, and I've read a lot of maintenance records for buyers. Most airplanes are honest. But the ones that aren't tend to share a handful of warning signs. None of these automatically means "walk away" — but every one of them means "stop and get this explained in writing before you go further."
1Missing logbooks or big undocumented gaps
The single most common value-killer. If a stretch of the airplane's life has no records, you cannot prove what happened during that time — damage, repairs, or nothing at all. Buyers, insurers, and lenders all treat "unprovable" as risk, and they price it that way. A missing engine logbook is bad; a missing airframe logbook is worse.
Missing records can knock a serious percentage off an aircraft's value — and they never get less missing. What's gone is gone.
2Signs of damage that nobody wants to talk about
A prop strike, gear-up, or hard landing leaves fingerprints even when it isn't spelled out: an engine teardown "for cause," a sudden major repair, a cluster of work all in one week, or a fresh FAA Form 337. If the airplane's history has an event-shaped hole in it and the seller gets vague when you ask, that's a flag.
3Airworthiness Directives that aren't complied with — or aren't tracked
ADs are mandatory. An applicable AD that was never complied with means the airplane isn't airworthy until it's fixed, on your dime. Just as telling: a recurring AD with no tracking, no method of compliance documented, and no next-due date. Sloppy AD records are a preview of how the whole airplane was maintained.
4Entries that don't add up
Times and dates across the airframe, engine, and prop logs should tell one coherent story. Tach times that go backward, an annual signed while the airplane was supposedly mid-overhaul, hours that jump inexplicably — contradictions mean either sloppy recordkeeping or something being papered over. Either way, you want it explained.
5An overhaul that's claimed but not documented
"Fresh engine" is a great selling line. The logbook should back it up: who did the overhaul, when, to what limits (new vs. service), and what was replaced. A major overhaul with no supporting paperwork is just a story — and stories don't hold value at resale or reassure your mechanic.
6Repairs and alterations without proper sign-off
Major repairs and alterations need proper documentation — the right form, the right sign-off, and where required, approved data. Modifications installed without an STC or field approval, or work with no return-to-service entry, can turn into a legal and airworthiness headache that becomes your problem the day you take ownership.
7Long periods of inactivity dressed up as "low time"
A low total-time or low-SMOH airplane sounds ideal — until you realize those low hours were spread over 15 years of sitting. Engines don't like sitting; corrosion doesn't show up as a logbook entry. When the hours are low but the calendar is long, I read the records much more carefully, not less.
Not sure how to read these in a real set of logs?
That's exactly what a logbook review is for. I'll go through the records and give you a written report of what's there, what's missing, and what to ask the seller — before you commit.
See the logbook review service →