FAR 21.608 — TSO Quality Manual
FAR 21.608 requires TSO authorization applicants and holders to submit an English-language quality system manual to the FAA for approval.
FAR 21.608 sets a documentation requirement for anyone applying for or holding a Technical Standard Order (TSO) authorization. A TSO authorization is FAA approval to produce a specific article (like a seatbelt, transponder, or instrument) that meets a published minimum performance standard.
Under this section, the applicant or holder must:
- Provide a manual describing its quality system to the FAA for approval.
- Write the manual in the English language.
- Make the manual retrievable in a form acceptable to the FAA.
Why it matters operationally: the quality manual is how the FAA verifies that the manufacturer has a repeatable, documented process for producing parts that consistently meet the TSO standard. Without an approved manual, the manufacturer cannot legally produce TSO articles. While most pilot students won't write a quality manual, understanding TSO authorization helps explain why certain installed equipment (avionics, life vests, ELTs) carries TSO markings and how the FAA ensures those parts are airworthy.