Technical Standard Order

TSO

Section 03: Certification & Approval Types

Definition

A minimum performance standard for specified articles (materials, parts, processes, appliances, or components) issued by the FAA under 14 CFR Part 21, Subpart O. A TSO defines the minimum performance criteria that an article must meet, typically by referencing industry standards (such as RTCA DO- documents or SAE standards). A TSO Authorization (TSOA) is issued to a manufacturer who demonstrates that their article meets the applicable TSO standard, authorizing them to produce and mark the article as TSO-approved.

Where This Shows Up

A TSOA is not by itself sufficient for installation of the article on a specific aircraft; the installation must still be approved under the appropriate type design approval (TC, STC, or field approval). The TSO approval addresses the article's inherent performance; the installation approval addresses its integration into a specific aircraft type design.

Primary Sources

14 CFR Part 21, Subpart O — Technical Standard Order ApprovalsFAA

FAA procedures for the issuance of TSO authorizations.

Artifacts Produced

TSO Authorization (TSOA)FAA

The formal authorization issued by the FAA to a manufacturer to produce articles that meet the applicable TSO standard.

Across Jurisdictions

FAA (United States)

14 CFR Part 21, Subpart O

The FAA issues TSO Authorizations under Part 21 Subpart O. The TSO index defines each TSO standard with its referenced technical standard.

EASA (Europe)European Technical Standard Order (ETSO)

Part 21, Subpart O, and CS-ETSO

EASA issues ETSO Authorizations under Part 21 Subpart O, with the ETSO performance standards defined in CS-ETSO. ETSO numbering largely corresponds to FAA TSO numbering.

Related Terms

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