14 CFR 39.27 - What do I do if the airworthiness directive conflicts with the service document on which it is based?

Regulations last checked for updates: Feb 10, 2026

Title 14 - Aeronautics and Space last revised: Dec 19, 2026

View all text of Part 39 [§ 39.1 - § 39.27]

§ 39.27 - What do I do if the airworthiness directive conflicts with the service document on which it is based?

In some cases an airworthiness directive incorporates by reference a manufacturer's service document. In these cases, the service document becomes part of the airworthiness directive. In some cases the directions in the service document may be modified by the airworthiness directive. If there is a conflict between the service document and the airworthiness directive, you must follow the requirements of the airworthiness directive.

authority: 49 U.S.C. 106(g), 40113, 44701

source: Docket No. FAA-2000-8460, 67 FR 48003, July 22, 2002, unless otherwise noted.

cite as: 14 CFR 39.27