FAR 21.51 — Type Certificate Duration
FAR 21.51 explains how long a type certificate remains in effect, including surrender, suspension, revocation, and FAA-set termination dates.
FAR 21.51 sets the rule for how long a type certificate stays valid. A type certificate is the FAA's approval of a particular aircraft, engine, or propeller design — it certifies that the design meets airworthiness standards.
Under this section, a type certificate remains effective until one of the following happens:
- It is surrendered by the holder
- It is suspended by the FAA
- It is revoked by the FAA
- A termination date is otherwise established by the FAA
In other words, there is no fixed expiration date built into a type certificate. It continues indefinitely unless one of these specific actions ends it.
Why it matters operationally: Manufacturers and owners rely on the type certificate to support continued production, airworthiness directives, and parts approval. Knowing that a type certificate has indefinite duration — but can be ended by FAA action — helps pilots and operators understand why design approvals stay relevant for decades, and why FAA enforcement actions against a design can have wide-reaching effects.