ARSA has shared an informative letter from FAA that, in the association's words, "addresses the relationship between technical data (i.e., engineering information) on the one hand, and methods, techniques and practices for performing maintenance and alterations on the other."
The letter, signed by FAA Flight Standards chief John Allen, is a response to questions posed some six years ago by Erickson Air-Crane (who, by the way, deserves a thanks from the U.S. Ski Team, among others, for its work to help make Vancouver white
in time for the Olympics). Writes ARSA:
Concurring with ARSA’s interpretation of the pertinent rules, the FAA concluded that the "how-to" instructions for performing maintenance and alterations contained in manufacturer’s manuals is already supported by approved technical data when such approval is required under sections 65.95(d)(1), 121.379(b), 135.437(b) and 145.201(c) (i.e., when performing major repairs and alterations). Because the technical data was approved under the design change procedures of part 21 there is no need to have the data re-approved via a field approval (block 3 of a Form 337), DER approval (Form 8110-3) or approval by another authorized designee. The FAA’s decision applies to thousands of existing manufacturers’ maintenance and overhaul manuals including Structural Repair Manuals, Aircraft Maintenance Manuals, Engine and Propeller Maintenance Manuals and Component Maintenance Manuals.
See the whole story, including FAA's complete response, here