TSO Manufacturing Facilities

FAR 21.609 — TSO Manufacturing Facilities

FAR 21.609 covers TSO authorization for manufacturing facilities, including overseas locations, FAA approval for moves, and required change notifications.

In Plain English

FAR 21.609 governs where a TSO (Technical Standard Order) authorization holder can manufacture articles and what they must do when things change at the factory.

Key points:

Foreign facilities allowed: An applicant can get a TSO authorization for manufacturing facilities located outside the United States, but only if the FAA determines there's no undue burden in administering the regulatory requirements at that location.
Approval before relocating: The TSO holder must get FAA approval before changing the location of any manufacturing facility. You can't just move the factory and tell the FAA later.
Immediate written notice of changes: Any change to the manufacturing facilities that could affect inspection, conformity, or airworthiness of the product must be reported to the FAA immediately, in writing.

Why it matters operationally: The FAA must be able to oversee production to ensure parts meet TSO standards. If a manufacturer moves or modifies its facility without notice, the agency loses confidence that articles being installed on aircraft still meet the approved design — directly affecting airworthiness in the field.

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Regulation Text

14 CFR § 21.609

§ 21.609 Location of or change to manufacturing facilities. (a) An applicant may obtain a TSO authorization for manufacturing facilities located outside of the United States if the FAA finds no undue burden in administering the applicable requirements of Title 49 U.S.C. and this subchapter. (b) The TSO authorization holder must obtain FAA approval before making any changes to the location of any of its manufacturing facilities. (c) The TSO authorization holder must immediately notify the FAA, in writing, of any change to the manufacturing facilities that may affect the inspection, conformity, or airworthiness of its product or article.

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Oral Exam Questions a DPE Might Ask

Q1Can a TSO authorization be issued for a manufacturing facility located outside the United States?

Yes. Under FAR 21.609, the FAA may issue a TSO authorization for facilities outside the U.S. provided it finds no undue burden in administering the applicable requirements.

Q2What must a TSO authorization holder do before relocating a manufacturing facility?

Per FAR 21.609(b), the holder must obtain FAA approval before making any change to the location of any of its manufacturing facilities.

Q3If a change at the factory could affect airworthiness of a TSO article, what is required?

FAR 21.609(c) requires the TSO authorization holder to immediately notify the FAA in writing of any change that may affect inspection, conformity, or airworthiness of the product or article.

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