86-07-13: Fourth Stage Compressor Vane Assemblies

86-07-13 AVCO LYCOMING DIVISION: Amendment 39-5265. Applies to Avco Lycoming ALF502L series turbofan engines. Compliance is required within the next 50 hours time in service after the effective date of this AD unless already accomplished within the last 50 hours time in service, and thereafter at intervals not to exceed 100 hours time in service from the last inspection. To prevent engine power loss due to release of fourth stage compressor vane airfoils into the compressor flow path, accomplish the following: (a) Inspect the fourth stage compressor vane assemblies, identified by Avco Lycoming Part Number (P/N) 2-100-040-27, for vane cracking at the outer shroud in accordance with Avco Lycoming Service Bulletin (SB) Number ALF502L-72-0137, dated March 27, 1986. (b) Remove from service, prior to further flight, those fourth stage compressor vane assemblies found with vane airfoils missing, or cracked or separated at the outer shroud. Aircraft may be ferriedin accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, Aircraft Certification Division, New England Region, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803. Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Manager, Engine Certification Office, Burlington, Massachusetts, may adjust the compliance time specified in this AD. Avco Lycoming SB Number ALF502L-72-0137, dated March 27, 1986, identified and described in this document, is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Avco Lycoming Division, 550 South Main Street, Stratford, Connecticut 06497. These documents also may be examined at the Office of the Regional Counsel, New England Region, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803. This amendment becomes effective on April 11, 1986.