FAR 21.313 — PMA Duration

FAR 21.313 sets the duration of a Parts Manufacturer Approval (PMA). Once the FAA issues a PMA, it stays in effect indefinitely — there is no fixed expiration date. The approval continues until one of three things happens:

• The PMA holder surrenders it voluntarily.
• The FAA withdraws it.
• The FAA otherwise terminates it.

Why does this matter operationally? A PMA authorizes a manufacturer to produce modification or replacement parts for installation on type-certificated aircraft. Because the approval has no built-in renewal cycle, operators and mechanics can rely on PMA parts as long as the approval remains active. However, the FAA retains continuing oversight authority — if the manufacturer fails to maintain quality control, conform to the approved design, or comply with applicable regulations, the FAA can withdraw or terminate the PMA. As a pilot or maintenance professional, this is why verifying that a part’s PMA is still in good standing matters when sourcing replacement components.