FAR 21.603 — TSO Application Requirements
FAR 21.603 explains how to apply for a TSO authorization, including required statements of conformance, technical data, and FAA deficiency response timelines.
FAR 21.603 sets out how a manufacturer applies for a Technical Standard Order (TSO) authorization — FAA approval to produce an article (like an altimeter, seat belt, or ELT) that meets a specific minimum performance standard.
To apply, the applicant must submit the application in the form and manner the FAA prescribes, along with:
- A statement of conformance certifying the applicant has met the requirements of this subpart and that the article meets the applicable TSO in effect on the date of application.
- One copy of the technical data required by the applicable TSO.
If the applicant expects a series of minor design changes under § 21.619, they can list the basic model number with open brackets after it, signaling that suffix letters or numbers will be added later as changes occur.
If the FAA finds the application deficient, the applicant must supply additional information when requested. Failure to respond within 30 days results in denial of the application.
Why it matters: TSO articles installed on aircraft must come from properly authorized manufacturers — this rule is the gateway that ensures parts in your panel meet FAA-approved standards.