Buying Aircraft Parts: New, Overhauled, Used, and PMA

The short version

For a certified aircraft, every part you install needs a documented pedigree showing it's airworthy — but "airworthy" doesn't always mean "new." Depending on the part, new, overhauled, serviceable used, and PMA (Parts Manufacturer Approval) parts can all be perfectly legal and appropriate choices. The right choice depends on what the part is, what condition it's in, and what paperwork comes with it.

The four categories

Why standard hardware is usually fine used

Bolts, nuts, washers, rivets, pins, and similar hardware made to AN, NAS, or MS specifications are commodity items manufactured to a published spec — there's no individual "history" to evaluate. If a bolt is the correct part number, isn't corroded, isn't stretched or thread-damaged, and isn't on a life-limit list, a used one is functionally identical to a new one. This is why salvage yards and hardware kits built from pulled hardware are a normal, accepted source for this category, and why this site labels standard hardware items "used acceptable" in the buying-advice section of each part page.

Why seals, hoses, and fluid-system parts are different

Rubber and elastomer components — O-rings, gaskets, diaphragms, hoses, and similar parts — degrade with age and chemical exposure, not just flight hours, and that degradation isn't always visible from the outside. A hose that looks fine can have an internal liner that's delaminating. For this reason, these parts are almost always treated as consumables: replace with new at every opportunity rather than reusing a pulled part, regardless of how many hours it shows.

Reading the paperwork

The single most important thing about any non-hardware part you buy is whether it comes with traceable documentation:

• FAA Form 8130-3 ("Airworthiness Approval Tag") — issued by a repair station or manufacturer, certifies the part's condition (new, overhauled, inspected/tested, or repaired) and ties it to a specific work order.
• Yellow tag — shop slang for an 8130-3 issued by a repair station after inspection, overhaul, or repair.
• Green tag — shop slang for a tag certifying the part as "as removed, serviceable" without further work, usually from an operator or parts dealer.
• Logbook traceability — for major components (engines, props, some accessories), the part's history should be traceable back through aircraft or component logbooks.

A part with no paperwork isn't necessarily bad metal, but it can't be installed on a certified aircraft with a clear airworthiness trail — and you have no way to confirm it isn't a life-limited part that's already past its limit, or one that was involved in an incident.

PMA parts: a legitimate way to save money

A PMA part is manufactured by a company other than the original OEM, under an FAA approval that covers either an identical design ("licensed PMA") or an independently-engineered equivalent ("design approval PMA"). PMA parts are new, come with their own 8130-3 or equivalent certification, and are legal replacements for the specific applications listed in the manufacturer's PMA approval — common examples include filters, brake pads, exhaust components, and various hardware items. The catch is applicability: a PMA part is only approved for the specific aircraft/engine models listed in its approval, so always check the PMA holder's eligibility list against your aircraft before buying on price alone.

Red flags when buying used or surplus

• No tag, no logbook reference, and the seller can't say where the part came from.
• A life-limited part (documented in the manufacturer's Airworthiness Limitations or an AD) with no time/cycle history.
• Visible corrosion, cracked paint over a repair, or mismatched fasteners suggesting prior unapproved work.
• A part number that doesn't match any effectivity code for your serial number — see our guide to reading an IPC for how to check this.
• Pricing dramatically below every other listing for the same part number with no explanation.