FAR 21.173 — Airworthiness Certificate Eligibility
FAR 21.173 explains who is eligible to apply for an aircraft airworthiness certificate, how to apply, and where to submit the application to the FAA.
FAR 21.173 sets the eligibility rules for applying for an airworthiness certificate — the document that legally allows an aircraft to be flown. The rule is short but important:
- Only the registered owner of a U.S.-registered aircraft (or the owner's agent) may apply.
- The application must be made in a form and manner acceptable to the FAA.
- It may be submitted to any FAA office.
Why this matters operationally: before an aircraft can carry you or passengers legally, it must have a valid airworthiness certificate on board (per FAR 91.203). That certificate originates from the application process described here. As a pilot, you may not be the one filing the paperwork, but you should understand that the owner controls this process. If you're buying an aircraft, you become the eligible applicant once the registration is in your name. Knowing this helps you trace the chain of documents — registration, application, airworthiness — that keeps an aircraft legal to fly.