FAR 21.621 — Imported TSO Articles
FAR 21.621 explains how the FAA issues letters of TSO design approval for articles manufactured abroad and imported into the United States.
In Plain English
FAR 21.621 governs how the FAA issues a letter of TSO design approval for an article that is designed and manufactured outside the United States and imported here. This rule matters because aviation parts are sourced globally, and the FAA needs a process to recognize foreign-built articles without compromising U.S. safety standards.
The FAA may issue a letter of TSO design approval for an imported article when:
- The article is designed and manufactured in a foreign country or jurisdiction that has an export agreement with the United States covering acceptance of these articles for import.
- The State of Design certifies that the article has been examined, tested, and found to meet the applicable TSO (Technical Standard Order) — or the State of Design's own performance standards plus any additional FAA-prescribed standards — to provide a level of safety equivalent to the TSO.
- The manufacturer has provided the FAA, through its State of Design, one copy of the technical data required by the applicable performance standard.
The letter the FAA issues will list any deviation that was granted under §21.618.
Regulation Text
14 CFR § 21.621§ 21.621 Issue of letters of TSO design approval: Import articles.
(a) The FAA may issue a letter of TSO design approval for an article—
(1) Designed and manufactured in a foreign country or jurisdiction subject to the export provisions of an agreement with the United States for the acceptance of these articles for import; and
(2) For import into the United States if—
(i) The State of Design certifies that the article has been examined, tested, and found to meet the applicable TSO or the applicable performance standards of the State of Design and any other performance standards the FAA may prescribe to provide a level of safety equivalent to that provided by the TSO; and
(ii) The manufacturer has provided to the FAA one copy of the technical data required in the applicable performance standard through its State of Design.
(b) The FAA issues the letter of TSO design approval that lists any deviation granted under § 21.618.
[Doc. No. FAA-2006-25877, Amdt. 21-92, 74 FR 53392, Oct. 16, 2009, as amended by Amdt. 21-92A, 75 FR 9095, Mar. 1, 2010]
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Oral Exam Questions a DPE Might Ask
Q1Under what conditions can the FAA issue a letter of TSO design approval for an article manufactured in a foreign country?
Per FAR 21.621, the article must be designed and manufactured in a country with a U.S. export agreement covering import acceptance, the State of Design must certify it meets the applicable TSO or equivalent performance standards, and the manufacturer must provide required technical data to the FAA through its State of Design.
Q2Who is responsible for certifying that an imported article meets the applicable TSO performance standards?
FAR 21.621(a)(2)(i) requires the State of Design to certify that the article has been examined, tested, and found to meet the applicable TSO or equivalent performance standards providing a level of safety equivalent to the TSO.
Q3If a deviation was granted for an imported TSO article, where would you find it documented?
Under FAR 21.621(b), any deviation granted under §21.618 is listed on the letter of TSO design approval that the FAA issues for the imported article.
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§21.15 Type Certificate Application
FAA application form, aircraft drawings, and engine data
§21.17 Certification Basis
Applicable airworthiness, noise, and emission rules
§21.20 Compliance Showing
How applicants show compliance to the FAA
§21.31 Type Design
Drawings, specifications, dimensions, and limitations
§21.41 Type Certificate
What the certificate includes once the design is approved
§21.47 Type Certificate Transferability
Transfer and licensing notices for FAA type certificates
Related Sections in Part 21