Home | 11 Ways to Get Legal Aircraft Parts or “Parts Ain’t Parts”

11 Ways to Get Legal Aircraft Parts or “Parts Ain’t Parts”

In the course of human events there comes a time when we need a part for maintenance or alteration of our aircraft. The traditional wisdom says to call the Manufacturer’s local dealer and order the part. Since many of the planes in today’s fleet are “orphans” because the factory that built them has closed, this is not always practical. More and more often even if there is still factory support for your plane, they may not have in stock the part you need, and they may not even plan to produce it again. In some cases (or so I have heard) the manufacturer has plenty of the part on the shelf, but the potential purchaser finds the price unacceptable. Where else can you get that part?The FAA has issued through FARs, Advisory Circulars, and Orders information that recognizes 11 ways to produce an “approved part”. Before discovering what those 11 ways are, let’s define an “approved part”. To be an approved part, the part in question must be “eligible for installation” on your plane, it must be of an approved design, properly produced, properly maintained, and properly documented.

This means that the part must be intended for the specific make and model it is about to be installed on, and that it must have had its design certified by the FAA, it must have been manufactured with the correct tools and data, it must be in new or properly altered condition as the result of any maintenance or overhauls performed on it, and it must have the proper paper trail to confirm each of the above steps. If the part lacks one or more of these factors, then it cannot be an “approved part”.

So, what are those 11 ways to produce approved parts?

Produced with a Parts Manufacturer Approval (PMA) issued under FAR 21.303

This is the standard means of producing an “aftermarket” part for an aircraft. It is the aircraft equivalent of going to NAPA for a part for your car. The part may be made by a contract supplier to the OEM, or it might be manufactured by someone totally unconnected with the original production. But in either case the producer has proven to the FAA that they are making a part that is identical in function to the OEM one, and therefore is worthy of the “PMA” (Parts Manufacturing Approval) designation. A manufacturer must have a separate PMA for each and every part number that they produce.

Produced in accordance with a Technical Standard Order (TSO) Authorization issued by the Administrator under FAR 21 Subpart O.

This is a part in which the Industry sets the standards to which a component must adhere to get the TSO stamp. It isn’t FAA controlled, but they do monitor the production of TSO’d items. The most common TSO’d items are avionics equipment, but some tires, seat belts, and other items are TSO’d.

Produced under Type Certificate (TC) without a separate production authorization and with Approved Production Inspection System (APIS) in accordance with FAR 21 Subpart F.

Suppose you own an aircraft such as a Swift or a Luscombe that has been out of production for decades, and the company that owns the TC is still making parts for the fleet, but they are not producing any new planes. They hold the TC but don’t have a Production Certificate, so they must meet special requirements (APIS) to insure that the parts conform to the TC. Univair is an example of this for many of the parts they sell. Also any company that is not in production, but is still making parts falls under this as well.

Produced during the TC application or the STC application process prior to the issuance of the certificate; and subsequently determined to conform to the approved TC or STC data. FAR 21.303 (b)(1).

These would be parts that the OEM made prior to the issuance of the type certificate by the FAA. Those parts hadn’t been “approved” at the time of manufacture because there was no standard to approve them under (no type certificate to check them for conformance). These could also be parts made by the developer of a proposed STC or field approval prior to receiving the approval.

Produced under a Production Certificate (PC) in accordance with FAR 21 Subpart G.

These parts would be parts that the OEM made for production planes or as spare parts. This is actually the most common method of producing an approved part. If you have ever purchased a replacement part from Cessna, Piper, Beech, Mooney, etc. then you have almost certainly purchased a part produced by this method.

Produced in accordance with approval under a BAA (bilateral airworthiness agreement) under FAR 21 Subpart N.

These would be parts produced in a foreign country that has worked with the FAA to show that their record keeping and quality control are equal to ours. (It’s a global market out there!) Much the same as they accept parts produced in the USA by approved manufacturers, we accept theirs. At last count there were 28 or 29 countries that have entered into a BAA with the USA.

Approved in any other manner acceptable to the Administrator FAR 21.305.

(Parts that have been maintained, rebuilt, altered, or overhauled, and approved for return to service in accordance with Parts 43 and/or 145 are considered to be approved parts. Parts that have been inspected and/or tested by persons authorized to determine conformity to FAA-approved design data may also be found to be acceptable for installation. These might include “military surplus” items.)

This is sort of a catch all method that would allow items with no traceability to be “conformed” to the type certificate and then entered into the supply line.

Produced as standard parts that conform to established industry or US specifications.

Items such as AN, MS, NAS hardware, and landing light bulbs, etc. are examples of “standard parts”. If there is a published standard (such as the AN or MS specs released by the government), and anyone that wishes to tool up to follow that spec and make the part can do so without license or copyright infringement, then it falls under this method.

Produced by an owner or operator for the purpose of maintaining or altering their own product.

This is a VERY important method, which is becoming vitally important as the fleet of certified planes age, and as more manufacturer’s go out of business. This provision allows the owner operator to produce your own part for use on your own plane, but is subject to the requirements that you must use the same materials and processes as the OEM did to produce the original. Many skins have been cut out of a sheet of 2024-T3 using this provision, but more complicated parts may also be produced this way. The catch is that you may NOT produce an “extra” one and sell it, and it is often hard to “reverse engineer” a part from the original. For example, what alloy was the OEM part made from, and did it have any heat treatment or corrosion resisting treatments?

Manufactured by a repair station or other authorized person during alteration in accordance with an STC or Field Approval, in accordance with FAR 43 and Order 8000.50 “Repair Station Production of Replacement or Modification Parts”.

Pretty much the same as owner produced part in #9. The list of who may produce the part is expanded to include certified repair stations. Though again they may not produce them for sale outside of their normal repair work. This also specifically gives repair stations the permission to alter the product per STCs or seeking field approval.

Fabricated by a qualified person in the course of a repair for the purpose of returning a product to service under FAR 43.

Again, like an owner produced part in #9, but it is specifically saying that an A&P or other maintenance worker can make a part if it is needed during maintenance to repair a product. Same caveat applies, that although the mechanic can charge you for his time and the materials to produce the part, he CANNOT make extra and sell them if he is not installing it in the course of his repair work.

These are the 11 ways that one can produce a legal part for a certified aircraft. The 11 cardinal points were taken directly from the “Suspected Unapproved Parts Seminar” handout provided by the FAA to all who attended one of the regional seminars hosted by the FAA. The “plain text” interpretations added after each point are either from the explanations given by the presenting FAA representatives or my explanation of what I read from the handout.

As explained to me, the FAA uses the same definition of “produce” as Hollywood does. The producer of a Movie does not usually play any of the lead roles, nor does the producer direct that acting or camera crews. The producer decides which script will be portrayed, who he wishes to direct the work, how the financing will be arranged, and in general is responsible for the outcome of the project. So it is when we put on our “producer” hat to make an aircraft part. We can locate the data that will be used to make the part, we can select someone to oversee the process, and we can supply the money and inspect the final product to insure that we got what we asked for and our money’s worth. We need not know how to form sheet metal, lay up fiberglass, weld steel tubing, use machine tools or even so much as how to hold a screwdriver. We only need know what the requirements are for the part and we are free to pay others to do the actual work of manufacturing the part to conform to the data we provided.

© Bob Steward 2000

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