FAR 21.139 — Manufacturing Facility Location
FAR 21.139 covers production certificate rules for manufacturing facility locations, FAA approval for moves, and required notifications of facility changes.
FAR 21.139 governs where holders of a production certificate (PC) can build aircraft, engines, propellers, or parts, and what happens when those facilities change. While this rule mostly affects manufacturers rather than pilots directly, understanding it helps you appreciate how the FAA ensures the aircraft you fly was built under controlled, inspected conditions.
The regulation establishes three key requirements:
- Foreign facilities allowed: An applicant may obtain a production certificate for manufacturing facilities located outside the United States, but only if the FAA determines there's no undue burden in administering Title 49 U.S.C. and the applicable airworthiness rules.
- Prior approval to relocate: The PC holder must get FAA approval before changing the location of any manufacturing facility.
- Immediate written notice: Any change to a facility that may affect inspection, conformity, or airworthiness of the product must be reported to the FAA immediately, in writing.
Operationally, this rule keeps the FAA in the loop on where and how certificated products are built, protecting the airworthiness chain that supports every flight you make.
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?