Sourcing Aviation Replacement and Obsolete Parts
In civil aviation the FAA, not just the buyer, decides whether a part can be installed. Replacement parts generally must come from a production approval such as a PC, PMA or TSO authorization, or qualify as standard parts, and must arrive with documentation that proves eligibility and traceability.
Why aviation parts are different
Civil aviation is the one aerospace market where a regulator, not only the customer, decides whether a part may be installed. A part that is dimensionally perfect can still be ineligible for a type certificated aircraft if it did not come from an approved production source or does not have the documentation to prove it. For buyers of replacement and obsolete parts that is the whole game: eligibility, traceability and paperwork first, then price and lead time.
The 14 CFR Part 21 framework in practice
Part 21 governs certification of products and articles and the production approvals behind them. For a parts buyer the relevant pieces are these:
| Route | What it means | Typical evidence |
|---|---|---|
| Production certificate (PC) holder | The type certificate holder or licensee producing under an FAA approved quality system per 14 CFR 21.137 | Authorized release document, often FAA Form 8130-3, or the holder's certificate of conformance as its system allows |
| Parts Manufacturer Approval (PMA) | Under 14 CFR 21.303, modification or replacement parts for sale for installation on a type certificated product generally must be produced under a PMA unless an exception applies | PMA marking on the part and the approved eligibility listing; release documentation per the holder's system |
| Technical Standard Order authorization (TSOA) | Articles produced under a TSO | TSO marking and release documentation |
| Standard parts | Parts conforming to an established industry or U.S. specification, such as NAS, AN, MS and SAE AS hardware | Manufacturer certificate of conformance to the specification |
| Owner or operator produced parts | Parts an owner or operator makes to maintain or alter its own product | Approved data and the operator's maintenance records; not for sale to others |
The 21.303(b) exceptions, as summarized in FAA guidance and the Federal Register, are parts produced under a type or production certificate, owner or operator produced parts, TSO articles and standard parts. FAA Advisory Circular 21.303-4 notes that PMA is not for base materials, processes or inspection procedures.
Production approval holders and their suppliers
A production approval holder must document a quality system under 14 CFR 21.137 that keeps each product and article conforming to its approved design. FAA Advisory Circular 21-20C explains that the holder's supplier control must ensure items from suppliers, including lower tiers, conform to approved design data, and FAA Order 8120.12 says that responsibility cannot be delegated by contract. That is why a job shop supplying a PMA holder will see a source approval visit, flowed down quality clauses, and often an FAI to AS9102.
FAA Form 8130-3: what it is and what it is not
FAA Form 8130-3, the Authorized Release Certificate or Airworthiness Approval Tag, is governed by FAA Order 8130.21. According to the order it can serve as an FAA statement that a new product or article produced under Part 21 conforms to its design and is in a condition for safe operation, as a return to service document for a used article after maintenance or alteration, and as an export approval under bilateral agreements. In every use it supports identification and traceability across the aviation system.
Points that trip up buyers:
- The status block and the release statement matter. A tag for a new part from a production approval holder and a tag issued by a repair station after overhaul make different statements. Read which release block is completed and who signed.
- Not every eligible part has an 8130-3. Standard parts usually arrive with a manufacturer's certificate of conformance. A PC holder may ship with its own certificate as its approved system allows.
- A tag does not cure an unknown history. A used part with a tag but a gap in its back to birth records can still be a problem for life limited items. Ask for the records the part type requires.
- Revisions change. Order 8130.21 has been revised several times; a 2025 industry rewrite references Revision J. Confirm the current revision on the FAA orders site before quoting a paragraph.
Eligibility and the advisory circulars buyers use
- AC 20-62E, Eligibility, Quality and Identification of Aeronautical Replacement Parts. Active, with Change 1 issued September 2018. It guides determinations of quality, eligibility and traceability for parts used on U.S. type certificated products, and defines terms such as standard part and new.
- AC 21-29D, Detecting and Reporting Suspected Unapproved Parts. Contains FAA Form 8120-11 for reporting. The FAA notes that a suspected unapproved parts report can no longer be started by phone and must be submitted by email or mail.
- AC 00-56B, Voluntary Industry Distributor Accreditation Program. Lets distributors be accredited to an acceptable quality standard, such as ASA-100 or the AS9100, AS9110 and AS9120 series, and listed in a database that the Aviation Suppliers Association manages for the FAA. Participation is voluntary but widely expected by operators.
Obsolete parts: the realistic options
When an OEM stops supporting a part, buyers usually have four paths, each with different regulatory weight.
- Surplus or used serviceable stock. Fastest when it exists. Requires a release document appropriate to condition, traceability to an approved source, and for used parts an inspection or overhaul by an appropriately rated repair station. Buy from accredited distributors where possible.
- Repair or overhaul of the existing unit. Often the cheapest route for components. Performed by a certificated repair station with the right rating, which returns the article to service.
- A PMA alternative. Some obsolete parts have approved PMA replacements from independent manufacturers. Check the PMA eligibility for your make and model.
- New manufacture under an approval. A part may be produced by the PC holder on a special run, by a PMA applicant who obtains approval through test and computation or identicality, or by an owner or operator for its own aircraft under approved data. A job shop alone cannot sell an unapproved copy for installation.
For parts that will never be installed on a type certificated aircraft, such as ground equipment, simulators or test rigs, these rules do not apply and a drawing based build is fine. Say so on the RFQ to avoid confusion. Defense and public aircraft operate under different rules again; see defense systems.
Counterfeit and suspected unapproved parts
Aviation counterfeit risk concentrates in bearings, fasteners, electronic components and high value rotables. Practical controls for a buyer:
- Buy from the manufacturer, its authorized distributors or AC 00-56 accredited distributors.
- Match part number, serial number and lot on the part, the tag and the packing slip. Check for altered or relabeled data plates.
- For fasteners and standard parts, require the manufacturer's certificate of conformance and lot traceability, not only a distributor's certificate.
- For electronics, AS5553 and the AS6081 and AS6171 family give detection and test practices.
- Report suspected unapproved parts to the FAA using Form 8120-11 under AC 21-29D.
More detail on what receiving inspectors look for is on receiving inspection and material certs and traceability.
Export considerations
Civil aircraft parts are mostly controlled under the EAR, while parts specially designed for military aircraft are on USML Category VIII or in the CCL 600 series. Exported civil parts may also need an 8130-3 issued for export under bilateral agreements. If your RFQ involves a military variant of a civil type, state the classification; see controlled programs.
What makes aviation parts hard
- Paperwork worth more than the metal. An eligible part with a broken record trail may be worth only its scrap value for installation.
- Approved data access. Shops can make a perfect part from a sample, but approved design data belongs to the approval holder. Reverse engineering for a PMA is a certification project, not a quote.
- Small, irregular demand. Legacy fleets need a few pieces at a time, which makes setup and FAI cost dominate.
- Life limited parts. Back to birth traceability is often required, and gaps cannot be filled after the fact.
Request help with an obsolete or hard to find part
Send the part number through the quote form under obsolete parts with the aircraft make and model, condition needed (new, overhauled, serviceable), the release documentation you require and the quantity. We search qualified sources, check the paperwork against your requirement and deliver with the certificate package, and a person replies within one business day. Related: industries hub and UAS and advanced air mobility.
Questions
Can a machine shop make a replacement part for a certificated aircraft from a drawing?
Not for sale for installation unless it is produced under an approval or an exception applies. Under 14 CFR 21.303, modification and replacement parts sold for installation on a type certificated product generally must be produced under a PMA. Exceptions include parts made under a type or production certificate, TSO articles, standard parts and parts an owner or operator makes for its own product. Shops commonly supply approval holders as controlled suppliers instead.
Does every aviation part need an FAA Form 8130-3?
No. The 8130-3 is one authorized release document. Standard parts usually ship with the manufacturer's certificate of conformance, and production approval holders release parts as their approved system allows. Used parts returned to service after maintenance typically carry a release from the repair station. What every installed part needs is documentation that supports eligibility and traceability, as described in AC 20-62E.
What is a suspected unapproved part and how is it reported?
It is a part that may not meet the requirements for an approved part, for example with questionable origin, falsified documents or evidence of improper manufacture. AC 21-29D gives guidance on detecting them and includes FAA Form 8120-11 for reporting. The FAA states that reports can no longer be started by phone and must be sent by email or mail.
What does AC 00-56 accreditation tell a buyer about a distributor?
That the distributor is accredited to an acceptable quality system standard, such as ASA-100 or the AS9100, AS9110 or AS9120 series, and is listed in the voluntary database the Aviation Suppliers Association manages for the FAA. It is voluntary and does not make every part the distributor sells eligible. Buyers still need to verify documentation and traceability for each part.
How is a PMA obtained for an obsolete part?
An applicant shows the FAA that the part meets airworthiness requirements, commonly through test and computation or through identicality with the original design, as described in AC 21.303-4, and establishes a production quality system. It is a certification effort that can take significant time and engineering. For one or two pieces, surplus stock, overhaul or a special run from the original approval holder is usually faster.
Are parts for ground support equipment and simulators subject to Part 21?
Generally no. Part 21 production rules apply to products and articles for installation on type certificated aircraft. Ground equipment, simulators, tooling and test rigs are bought to the buyer's drawings and quality requirements. State on the RFQ that the part is not for installation so suppliers do not price in certification paperwork that is not needed.
Related
Sources
- FAA Order 8130.21, Procedures for Completion and Use of FAA Form 8130-3
- ARSA and AEA rewrite of FAA Order 8130.21J (2025)
- FAA AC 21.303-4, Application for PMA via Tests and Computations or Identicality
- Federal Register, February 27, 1995 notice on 21.303 exceptions
- 14 CFR 21.137, Quality system (eCFR)
- FAA AC 21-20C, Quality system and supplier control guidance
- FAA Order 8120.12
- FAA AC 20-62E with Change 1
- FAA AC 21-29D, Detecting and Reporting Suspected Unapproved Parts
- FAA Voluntary Industry Distributor Accreditation Program (AC 00-56)
- Aviation Suppliers Association: FAA AC 00-56 accredited companies
- DLA briefing on SAE counterfeit standards AS5553 and AS6174
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