Technical Amendment; Airworthiness Standards: Aircraft Engines; Correction

The FAA is correcting a technical amendment published on July 5, 2012 (77 FR 39623). In that technical amendment, the FAA clarified aircraft engine vibration test requirements in the airworthiness standards. The technical amendment was in response to inquiries from applicants requesting FAA engine type certifications and aftermarket certifications, such as supplemental type certificates, parts manufacturing approvals, and repairs. We revised the regulation to clarify that engine surveys require an engine test. Representatives of industry suggested that our technical amendment was in fact, a substantive change in the regulation, not a clarification. The FAA is correcting our prior action in response to that industry claim. This document amends the FAA's regulations to reverse the changes to Sec. 33.83(a) amendment 33-33 and restore Sec. 33.83(a) to its previous amendment 33-17.