TC / STC
- WHAT IT IS
- A Type Certificate (TC) is FAA approval of a new aircraft, engine, or propeller design as meeting the applicable airworthiness standards. A Supplemental Type Certificate (STC) approves a major change to a product that already holds a TC.
- WHY IT MATTERS
- Without a TC or STC, an aircraft, engine, propeller, or major modification cannot be operated commercially in the United States. It is the foundational approval that everything else in this route refers back to.
- TYPICAL DURATION
- Full TC programs for new aircraft or engines are typically measured in years; a well-scoped STC is commonly cited as roughly 12–24 months. Both vary widely with product novelty and authority workload.
Timelines above are broad, illustrative ranges only. Actual duration depends on product complexity, scope, prior program experience, and current authority or certification-body workload. They are not commitments, guarantees, or estimates of any specific program.
WHERE COMPANIES GET STUCK
Companies often treat this as a submission to file once the design is finished. In practice, the certification basis and means of compliance have to be agreed with the FAA (directly or through a DER) well before the design is frozen — arriving with a finished design usually means expensive rework, not a faster review.
