Buying a used aircraft: the pre-buy inspection

Most used-aircraft disasters are not dramatic failures in flight. They are a corroded spar, an undocumented engine overhaul, a prop with an unrecorded repair, or a logbook that quietly lost 400 hours. All of it is findable on the ground — if somebody looks before the check clears.

Why you do not skip it

A pre-buy turns a sales pitch into a written report. It gives you three things: a real condition picture, a realistic list of what the aircraft will need in the first year of ownership, and grounds to renegotiate or walk away. Even a clean report is a useful document — it is the baseline you will maintain the aircraft against.

Who should do it

• A mechanic who has no commercial interest in the sale — not the seller's shop, and not the person who will do the work later if you can avoid it.
• Someone who has worked on that make and model before, or who is willing to read the service bullets and the type documentation while they look.
• For an aircraft with a complicated history, a logbook review by a specialist can be done in parallel and is far cheaper than an engine teardown.

What to look at

• Structure and corrosion: spar areas, wing roots, tailpost, control tube ends, landing-gear attachments, and any evidence of a repair that was never documented.
• Engine: compression across all cylinders, a borescope look at the cylinders, oil and filter condition, mounts and lines, and whether the claimed time since overhaul is supported by paperwork.
• Propeller: blade condition, nicks and repairs, hub and governor condition, and the prop logbook's own history.
• Avionics: whether the installation is on an STC or a 337, whether the wiring looks like an installation and not a patch, and whether the databases are current.
• Landing gear and brakes: shrink tube and seals, tire and brake wear, shimmy and slop.
• General condition: paint that is hiding something, a cabin that suggests hard use, and evidence of water or hangar leaks.

The records are half the value

• Do the logbooks tell a continuous story, or do hours jump and entries disappear?
• Are the aircraft, engine and propeller times consistent with the tachometer and Hobbs readings?
• Is there a compliance record for every airworthiness directive that has ever applied?
• Are major repairs and alterations documented with a 337 or equivalent, and are damage history disclosures on the table?
• Is the last annual or 100-hour entry signed with a legible certificate number, and is the aircraft current?

How the process should run

1. 1Agree in writing, before anything starts, who pays for the pre-buy and what happens if it finds serious defects.
2. 2Give the mechanic a written scope: what you want examined, what you want photographed and what you want in writing.
3. 3Have the aircraft go to the inspecting shop, not just a hangar visit with the seller standing there.
4. 4Ask for a written report with photos, a list of defects, and a separate list of items that will need attention in the first year.
5. 5Use the report: fix items before closing, take a price reduction, or walk away. Do not 'deal with it later'.

After you buy

• Get the physical records in your hands at closing, not 'mailed later'.
• Transfer registration and airworthiness certificates into your name before you fly.
• Enter the pre-buy findings as tracked items so the punch list does not evaporate.
• Set up your own due-date calendar from day one: annual, ELT, transponder, altimeter and any hour-based item.