FAR 21.20 — Type Certificate Compliance
FAR 21.20 explains what a type certificate applicant must do to show and certify compliance with all applicable airworthiness requirements to the FAA.
FAR 21.20 sets out what an applicant for a type certificate (TC), amended type certificate, or supplemental type certificate (STC) must do to obtain FAA approval for an aircraft, engine, or propeller design.
Under this rule, the applicant must:
- Show compliance with all applicable airworthiness and certification requirements, and
- Provide the FAA the means by which compliance has been demonstrated (such as test data, analyses, and inspections), and
- Submit a statement certifying that the applicant has complied with those applicable requirements.
Why it matters operationally: as a pilot, you fly aircraft that received their TC under this process. The aircraft's type design — and any later modifications via STC — is only legal because the manufacturer or modifier proved compliance under FAR 21.20. When you sign off a logbook entry referencing an STC, you're relying on this certification chain. Understanding it helps you appreciate why unapproved alterations are a serious airworthiness issue.