FAR 21.320 — PMA Quality System Changes
FAR 21.320 explains how PMA holders must handle quality system changes, including FAA review and immediate written notice for changes affecting airworthiness.
FAR 21.320 governs what happens after the FAA issues a Parts Manufacturer Approval (PMA) when the holder wants to change its quality system — the documented procedures used to make sure each part conforms to its approved design and is airworthy.
Under this section:
- Every change to the quality system is subject to FAA review. The PMA holder cannot simply modify its inspection or production procedures in isolation; the FAA retains oversight authority.
- The PMA holder must immediately notify the FAA in writing of any change that may affect the inspection, conformity, or airworthiness of the article being produced.
Operationally, this matters because PMA parts are installed on certificated aircraft. If a manufacturer alters how parts are inspected or built without FAA awareness, undetected defects could enter the fleet. The rule keeps the FAA in the loop so quality control stays tied to the originally approved design and production standards.