[1] It is generally illegal in the United States to install replacement or modification parts on a certificated aircraft without an airworthiness release such as a Supplemental Type Certificate (STC) or Parts Manufacturing Approval (PMA).
Identicality by Licensure is accomplished by providing evidence to the FAA that the applicant has licensed the part data from the OAH.
As an example: If an STC were granted to alter an existing aircraft design then that approval would also apply to the parts needed to make that modification.
[6] The cognizant regional FAA Aircraft Certification Office (ACO) determines if the applicant has shown compliance with all relevant airworthiness regulations and is thus entitled to design approval.
[7] A Production Approval Holder (PAH) will typically already have satisfied this requirement before PMA application is made.
Under the Civil Air Regulations (CARs), the government had the authority to approve aircraft parts in a predecessor to the PMA rules.
This authority was found in each of the sets of airworthiness standards published in the Civil Air Regulations.
[12] The 1965 regulatory change also imposed specific obligations on the PMA holder related to the Fabrication Inspection System.
Accomplishing this harmonization of standards was an important goal of the Modification and Replacement Parts Association (MARPA).
[23] Today, all FAA production approvals – whether for complete aircraft or for piece parts – rely on a common set of quality assurance system elements.
The United States has Bilateral Aviation Safety Agreements (BASA) with most of its major trading partners, and the standard language of these BASAs requires the trading partner to treat FAA-PMA as an importable aircraft part that is airworthy and eligible for installation on aircraft registered in the importing jurisdiction.
[28] This process has been facilitated by the International Air Transport Association (IATA) which has published a book on accepting PMA parts.
[29] Although the PMA industry began in the United States, several countries have begun promoting production of approved aircraft parts within their own borders.