Frequently Asked Questions
The following answers are provided strictly as a primer for your basic understanding. We have intentionally omitted as much technical jargon as possible for ease of use. Accordingly, we have left out the specific supporting F.A.A. CFR (Code of Federal Regulations) references but if you want these references, we’ll be happy to provide them to you. We strongly encourage you not to rely only on our interpretations and explanations of the regulations, but direct you to check with your F.A.A. representative or find the F.A.A. on the web at www.fedworld.gov or www.faa.gov.
FAQ: Title if needed
FAA-PMA stands for Federal Aviation Administration Parts Manufacturing Approval. It is most easily thought of as a FAA manufacturing license and is one method by which the FAA conveys airworthiness to an aircraft part. A PMA part is typically a replacement for an Original Equipment Manufacturers (OEM) part. FAA-PMAs are non-exclusive approvals, but there is a high barrier to entry to obtain them. A FAA-PMA holder must demonstrate to the FAA that their replacement part is equal to or better than the part it replaces.
TSO is a Federal Aviation Administration designation which stands for Technical Standard Order. It is another method by which the FAA conveys airworthiness to an aircraft part. Very often (but not always) a TSO part is a replacement for an original part. A TSO produced part must only meet minimum prescribed FAA mandated standards or requirements.
There are a couple of important differences. An FAA-PMA part carries a requirement for the PMA holder to document to the FAA where this part can be used on the aircraft, engine or propeller, and to show it on the PMA supplement letter and parts packaging. This is referred to as the part’s “eligibility.” With a TSO the installer makes the decision on where the part is used. Another difference between PMA’s & TSO’s is the nature of their approval. In the most basic terms, a PMA holder is providing a part by demonstrating to the FAA that the part he is producing is equal to or better than the original (OEM) part it replaces. In contrast, a TSO produced part must only meet minimum prescribed FAA mandated standards or requirements.
FAA-PMAs are rapidly gaining acceptance around the world as more customers have come to rely upon the quality, performance, availability, cost savings of PMA and TSO parts. If you have any doubts or reservations, please check with your Quality Control Manager and FAA-PMI (Principle Maintenance Inspector) or contact us to arrange a time when we can meet with your Quality Manager or Engineers to discuss the use and benefits of PMA components in detail.
At ACD, our policy is to always make sure we tell you when we quote you the part, before you buy it. Look on our quotes under: Quoting: Alternate Part Number. This is one indication that we will provide a PMA or TSOA part. We also provide a verbal or written statement with the quotation.
According to FAA definition, a standard part is defined as AN, MS or NAS specifications. It is important to understand that these are Standards, not part numbers. Part numbers made to a Standard meet the Specifications of the applicable standard. Typically each bearing manufacturer is qualified (QPL) to produce the parts and appears on a QPL Listing. A Manufacturer that produces a part to a Mil Spec will provide their own part number that conforms to the respective AN, MS or NAS number.
It is important to understand that when you order an MS part number, you are in fact ordering a Military Standard Specification part number. In every case, you will receive the part number of the QPL manufacturer that corresponds to the respective Mil Spec. Published interchanges are readily available to support the interchanges, and often we can provide that documentation. But to be sure, make sure you request it prior to placing your order.
Not by FAA definition. Only AN, MS, or NAS parts currently are defined as Standard Parts.
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