How to Verify a Used Aircraft Part Is Airworthy
TL;DR
- • The part, its markings and its paperwork must all agree — if one disagrees, stop
- • An airworthiness release names who approved the part and under what authority
- • Traceability matters as much as the release: where did the part come from?
- • A PMA part is eligible only if its approval names your make and model
- • Missing identification, corrosion or an undocumented life limit makes a part scrap
A used part can be an easy way to get an aircraft back in service, and it can also be the reason an aircraft fails its next inspection. The difference is rarely the part itself. It is whether the paperwork, the markings and the physical condition tell the same story.
The checks below work in a specific order on purpose. Each one is cheaper and faster than the one after it, so the sooner you find a problem, the less time you spend on a part you were never going to install. Work through them in sequence and most bad parts reveal themselves before you have unwrapped them.
1. Match the part number to the paperwork
Start with the part number stamped, etched or printed on the part itself and compare it against the part number written on the release document. They must be identical, not merely similar. Manufacturers use suffixes and dash numbers to distinguish configurations that look alike and are not interchangeable, so a trailing character is a substantive difference rather than a clerical one.
If the paperwork lists a number the part does not carry, you have either the wrong paperwork or the wrong part. Neither is something to resolve after installation.
2. Match the serial number
For serialized components the serial number is what ties this specific part to this specific history. A release document that covers a different serial number is a document about a different part, even when the part number is right and the seller is confident the records got mixed up. The serial number is also what lets a shop look up whether the component is affected by an airworthiness directive or service bulletin.
3. Confirm the identification markings are intact
Identification has to be legible and it has to be original. Look for a data plate, etching or permanent marking that has not been polished, painted over, re-stamped or replaced with a sticker. Markings that have been obscured during refinishing are a problem even when the intent was innocent, because a part that cannot be positively identified cannot be positively approved.
4. Require an airworthiness release
The release is the document that states a qualified party found the part airworthy. In the United States that is typically an FAA Form 8130-3, and for parts arriving from Europe an EASA Form 1 serves the same purpose. What matters is that the document names who performed the approval, under what authority, and for which part and serial number.
One caveat worth knowing: an 8130-3 is a release, not an installation approval. It tells you the part was found airworthy by someone authorised to say so. It does not tell you the part is eligible for your aircraft, which is a separate check covered further down.
A yellow tag is not a substitute either. Tags are useful for identifying what a part is and who last handled it, but on their own they are not an approval for return to service.
5. Establish traceability
Traceability answers a simple question: where did this part come from? A clean chain runs back to a manufacturer, a repair station, an operator or a teardown with records. A chain that stops at “bought it from a guy” is not a chain. The FAA's Suspected Unapproved Parts program exists because parts with no verifiable origin do reach the market, and the cheapest point to catch one is before it is installed.
6. Verify the part is approved for your aircraft
Eligibility is specific to make and model. A part that is genuine, well documented and in excellent condition is still not installable if its approval does not cover your aircraft. Check the approval basis against your airframe or engine rather than assuming that a part which physically fits is a part which legally belongs.
7. Account for life limits and shelf life
Life-limited parts carry a finite number of hours or cycles, and a used one is only worth what remains. If the records do not show the time accumulated, the remaining life is unknown, and an unknown remaining life on a life-limited part means the part cannot be used. The same logic applies to anything with a shelf life, including seals, hoses and other elastomeric components that age on the shelf whether or not they were ever installed.
8. Inspect the physical condition
Only after the paperwork holds up is it worth spending time on a careful physical look. Check for corrosion, cracks, heat discolouration, galling on mating surfaces, damaged threads and any sign of a repair that is not reflected in the records. Confirm protective caps and packaging arrived intact, because a component that was shipped open may have taken damage or contamination in transit.
PMA parts: approved, but only for what the approval says
A Parts Manufacturer Approval part is produced by a company other than the original manufacturer under an FAA approval for that specific part and application. PMA parts are legitimate and widely used, and treating them as inherently inferior to OEM parts is a misreading of what the approval means.
The discipline required is narrower than that. The approval covers particular aircraft, so the question is never whether a PMA part is acceptable in general but whether this PMA part is approved for your make and model. The FAA publishes PMA listings in its Dynamic Regulatory System, where approvals can be searched by holder, article, approval basis and the make and model the part may be installed on. Confirm the application named there and the part is as eligible as any other.
When to walk away
Some findings end the conversation. Illegible or altered identification, a release that does not match the part in front of you, no traceable source, corrosion or heat damage, evidence of an unapproved repair, or a life-limited part with no documented time remaining. Each of these makes the part scrap on its own, and a low price does not offset any of them. The expensive outcome is not the part you declined to buy — it is the one you installed and then had to remove.
Receiving checklist
Run this before a used part goes on the shelf or into an aircraft.
- Part number on the data plate matches the release document
- Serial number on the data plate matches the release document
- Identification markings are legible and unaltered
- Airworthiness release present (FAA Form 8130-3, EASA Form 1, or equivalent)
- Traceability documented back to a known, named source
- Part is approved for your specific make and model
- Life-limited parts show time or cycles remaining in the records
- No corrosion, heat damage, cracks or evidence of unapproved repair
- Packaging and protective caps intact, with no shipping damage
- Shelf-life items are within date
Print this page to get the checklist on its own sheet.
How Michigan Aviation's parts team verifies parts
Our parts department runs the same sequence on everything that arrives, whether it came from a manufacturer, a repair station or a used market. Paperwork is matched to markings before a part is accepted, eligibility is checked against the aircraft it is destined for, and anything that cannot be positively identified does not get put into stock.
That is also why we keep common items on the shelf at KPTK. Having the part already verified and in stock is what turns a potential grounding into a scheduled repair, and it means owners are not deciding whether to gamble on an undocumented part at the worst possible moment.
Frequently Asked Questions
How do I verify a used aircraft part is airworthy?
Match the part to its paperwork before anything else. Confirm the part number and serial number on the data plate are the same ones written on the release document, then verify the part is approved for your aircraft and inspect its physical condition. If any of the three disagree, stop.
What paperwork should come with a used aircraft part?
An airworthiness release such as an FAA Form 8130-3 or an EASA Form 1, plus traceability back to a known source. Serviceable parts should carry a maintenance release naming who approved them and under what authority. A yellow tag alone is not an approval document.
Is a PMA part as good as an OEM part?
A PMA part is FAA-approved for the application listed in its approval, so it is legally installable on the aircraft it covers. The requirement is that the approval actually names your make and model. A PMA part approved for a different aircraft is not eligible, regardless of how similar it looks.
What makes a used aircraft part unusable?
Missing or illegible identification, no traceable paperwork, corrosion or heat damage, evidence of unapproved repair, or a life-limited part with no record of time remaining. Any one of these makes the part scrap. Price does not change the answer, and neither does a seller who vouches for it verbally.
Can I install a part I bought from an online marketplace?
Only if it arrives with the same documentation you would demand from a distributor. Marketplace listings often show a photo and a part number and nothing more. Treat the listing as a starting point and require the release paperwork and traceability in hand before the part goes anywhere near the aircraft.