Four ways to gain Parts Manufacturer Approval

A Parts Manufacturer Approval, or PMA, is a combined design and production approval for modification and replacement articles. Once a manufacturer receives a PMA, it allows them to manufacture and distribute these articles for use on type certificated products. A PMA is not only an approval of the aircraft parts manufacturing process itself, but serves as the FAA’s approval to manufacture specific aviation-related parts. It is issued for the production of parts to be used to modify or replace other parts, which includes materials, parts, processes, and appliances.

As the aerospace and aviation industries are highly-regulated, obtaining approval from the FAA is not exactly a simple process. In all cases, the manufacturer must first prove they are not only able to produce the aircraft part, but have a well-functioning production system in place and are able to consistently meet design specifications and airworthiness requirements. Furthermore, the manufacturer must also ensure traceability of each part throughout the entire process. There are four ways through which a manufacturer can seek FAA approval and acquire a PMA approval: supplemental type certificate, licensing agreement, identicality, and test & computation.

The first way to obtain PMA approval is through a supplemental type certificate, or STC. Approval of significant changes in the type design of an aircraft is received in the form of an STC. Gaining a PMA through an STC is the simplest path with the least amount of resistance. Because STC parts are already designed and approved, the process of gaining a PMA only involves verifying the manufacturer’s ability to produce the part to FAA-approved design standards. A second way to obtain parts manufacturer approval is to do so through licensing agreement. Occasionally, manufacturers must obtain a PMA by using the design data from a different company that already owns an STC for the specified part. In these cases, the two manufacturers can enter into a licensing agreement which states that the manufacturer will produce parts with their PMA capabilities but in accordance with the other manufacturer’s design.

A third way to gain PMA approval is through identicality. In certain instances, the original design data used to produce the part may not be available. In these cases, if a manufacturer is able to design a replacement part and prove that their manufacturing capabilities will allow them to produce a part identical to the original approved part, they can obtain a PMA based on identicality. To gain approval through identicality, a manufacturer must be able to prove that the part being designed and produced is identical in function, dimensions, materials, and so on. The advantage of PMA through identicality is that the approval process is easier than test and computation, though it is still difficult to prove complete identicality.

The final way to obtain PMA is through test and computation. This method is often a last resort when manufacturers are unable to prove identicality. In this method, the manufacturer produces new design data similar to, but not identical to, the original design. The manufacturer must then substantiate their design through testing and/or computation, much like the process of acquiring an STC. In the testing process, parts are scrutinized under different conditions to determine their compliance and airworthiness. In the computation process, the part’s design is examined through research and statistical analysis.

No matter how a part achieves PMA approval, its value is immediately increased by doing so. For PMA parts of all types, look no further than Purchasing Sphere. Owned and operated by ASAP Semiconductor, we can help you find an unparalleled selection of parts for the aerospace, civil aviation, and defense industries. Dedicated account managers are always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at or call us at 1-714-705-4780.


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