FAR 21.121 — Production Under Type Certificate
FAR 21.121 sets the applicability of FAA rules for aircraft production under a type certificate. Key reference for pilots studying Part 21 certification.
In Plain English
FAR 21.121 is a short but important opening section of Subpart F of Part 21. It simply states that this subpart prescribes the rules for production under a type certificate.
In plain terms:
- A type certificate (TC) is the FAA's approval that a particular aircraft, engine, or propeller design meets airworthiness standards.
- Once a TC is issued, the manufacturer needs FAA-approved procedures to actually build that product in series.
- Subpart F (which begins at 21.121) lays out those production rules — quality control, inspections, FAA oversight, and limits on how many units can be built before a Production Certificate is required.
Why it matters operationally: As a pilot, you'll fly aircraft that were built under these rules. The airworthiness data plate, the standard airworthiness certificate, and the assurance that your airplane matches its approved type design all trace back to compliance with this subpart. Understanding 21.121 helps you see the regulatory chain from design approval to the airplane on the ramp.
Regulation Text
14 CFR § 21.121§ 21.121 Applicability.
This subpart prescribes rules for production under a type certificate.
Oral Exam Questions a DPE Might Ask
Q1What does FAR 21.121 cover?
FAR 21.121 is the applicability section stating that Subpart F of Part 21 prescribes the rules for production under a type certificate.
Q2Where in the FARs would you look for the rules governing production of an aircraft under a type certificate?
You would look at Subpart F of Part 21, which begins with FAR 21.121 establishing applicability for production under a type certificate.
Q3Does FAR 21.121 itself spell out specific production requirements?
No. FAR 21.121 only states the applicability of the subpart; the specific production requirements are found in the sections that follow within Subpart F of Part 21.
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Related Sections in Part 21