What logbook red flags should I look for when buying a plane?

Short answer: The biggest logbook red flags are missing or "replacement" logbooks, unexplained gaps in time or dates, no current AD status list, modifications without Form 337s or STC paperwork, signs of damage history, and an engine that sat unused for long periods. Any one of these can cost more than the inspection itself, and some can make an airplane hard to insure or resell.

What records should exist?

Under 14 CFR 91.417(a)(2), the owner must keep, and transfer with the aircraft when it is sold (14 CFR 91.419):

• Total time in service of the airframe, each engine, and each propeller
• Current status of life-limited parts
• Time since last overhaul of items required to be overhauled on a specified time basis
• Current inspection status, including time since the last required inspection
• Current status of applicable airworthiness directives, including method of compliance
• Copies of the forms prescribed by 14 CFR 43.9(d) for each major alteration (Form 337)

If any of these are missing, that is the first red flag.

The red flags, ranked by how much they can cost

1. Missing or re-created logbooks. "Lost in a hangar fire" or a fresh set of logs starting a few years ago means you cannot verify history: damage, overhauls, AD compliance, or total time. Reconstructing records is possible but expensive, and many buyers and lenders walk away.

2. Gaps in time or dates. Look for periods with no entries, tach or Hobbs times that go backward, or annuals more than 12 calendar months apart without explanation. A long gap can mean the aircraft sat, was damaged, or was flown out of annual.

3. No current AD status list. The AD list should cover airframe, engine, propeller, and appliances, with method of compliance and next-due for recurring items (14 CFR 91.417(a)(2)(v)). A one-line "all ADs complied with" entry is not an AD list.

4. Modifications without paperwork. Every major alteration should have a Form 337, and every STC installation should have its STC documentation and updated weight and balance. Common examples: engine or propeller changes, avionics with antenna or panel modifications, speed mods, and fuel tank changes. Undocumented mods can make an aircraft unairworthy until fixed.

5. Signs of damage history. Look for entries mentioning wing, spar, gear, or prop strike repairs, sudden prop or engine replacements, or large structural Form 337s. A damage history is not automatically a deal-breaker if the repair was well documented, but it affects value and must be priced in.

6. Engine overhaul questions.

• Who did the overhaul? A recognized engine shop or a field overhaul with limited documentation?
• Is it labeled "zero time"? Under 14 CFR 91.421, only the manufacturer or an agency it approves can rebuild an engine and issue a new, zero-time record. A field overhaul keeps the engine's total time history.
• How old is it in calendar years? Both Lycoming and Continental publish calendar-time limits alongside hourly TBO, typically 12 years, because engines that sit deteriorate.

7. Low hours over many years. An engine with 300 hours in 10 years is not "low time"; it may be a corrosion risk. Look at flight frequency, not just total hours.

8. Vague entries. "Annual complete, all ok" with no list of what was found and fixed, repeated squawks that never get resolved, or the same recurring item replaced over and over.

9. Propeller history. Propellers often have their own overhaul recommendations and ADs. Check for a propeller logbook and overhaul records.

What is not a red flag by itself?

• High total airframe time, if maintenance has been consistent
• Engine past TBO, if priced accordingly and it passes a thorough evaluation (for Part 91 operators, manufacturer TBO is generally not mandatory)
• Several shops in the history, as long as the entries are complete

What should I do if I find one?

Do not assume it is fatal, and do not assume it is fine. Have an independent inspector review the records before you pay for a full physical inspection, and get estimated costs to resolve anything you find. The answer often becomes a negotiation point rather than a deal-breaker.

How Wingman handles it

Wingman AeroCare's ClearBuy pre-purchase inspection starts with the engine and records, with a stop/go gate before you spend money on Phase 2. The Remote option is a records review only, which is useful when the airplane is far from Northern Colorado. Remote delivers a written records memo with a proceed, caution, or do-not-proceed call; the onsite packages add a full written report, photo evidence pack, cost-to-correct ranges, and a debrief call, and findings are never shared with the seller without your permission. See pre-purchase inspections or call (970) 292-0719.