FAR 21.177 — Airworthiness Certificate Amendment
FAR 21.177 explains how an airworthiness certificate can be amended or modified—only by formal application to the FAA. Quick guide for pilot students.
FAR 21.177 is short but important: an airworthiness certificate can only be amended or modified by submitting an application to the FAA. In other words, neither the owner, operator, nor a mechanic can simply change what's printed on the certificate on their own — any change has to go through the FAA's formal process.
Why it matters operationally:
- The airworthiness certificate is one of the required documents that must be onboard the aircraft (remember ARROW).
- If the aircraft's category, type, or other certificated details change (for example, after a major modification or change in operating category), the certificate must be updated through the FAA — not by hand or by a third party.
- Flying with an altered or unauthorized certificate could render the aircraft not airworthy and the flight illegal.
Bottom line: any change to the airworthiness certificate is an FAA-only action, initiated by an application from the owner or operator.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?