86-15-04: Stage 1 High Pressure Turbine (HPT) Disks

86-15-04 GENERAL ELECTRIC COMPANY: Amendment 39-5353. Applies to General Electric CF6- 80A/A1/A2/A3 turbofan engines. Compliance is required as indicated, unless already accomplished. To prevent cracking or uncontained failure of stage 1 high pressure turbine (HPT) disks, Part Numbers 9234M67 and 9367M45, inspect those serial number disks identified in, and in accordance with, General Electric CF6-80 Alert Service Bulletin (ASB) 72-446, dated June 1986, per the following schedule: (a) Disks that have been previously inspected at the forward side embossment per Service Bulletin (SB) 72-248, dated August 12, 1983, or FAA approved equivalent, must be inspected at the aft side embossment at the next HPT exposure, or prior to accumulating 5,300 service cycles since new, whichever occurs first. (b) Disks that have not been previously inspected at the forward side embossment per SB 72-248, dated August 12, 1983, or FAA approved equivalent, must be inspected at both the forward and aft side embossments at the next HPT exposure, or prior to accumulating 5,000 service cycles since new, whichever occurs first. (c) Remove from service, prior to further flight, any disk with a tool mark or crack indication. NOTE: Disks that have been previously inspected at both the forward and aft side embossments per CF6- 80A Series Engine Manual GEK72501, Section 72-53-02, are in compliance with the inspection requirement of ASB 72-446 and do not need to be reinspected. Aircraft may be ferried in 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, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. General Electric ASB 72-446, dated June 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 obtained this document from the manufacturer, may obtain copies upon request to General Electric Company, Director of Product Support, 111 Merchant Street, Cincinnati, Ohio 45246. This document may also be examined at the Office of the Regional Counsel, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803, Room 311, Rules Docket Number 86-ANE-23, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. This amendment, 39-5353, becomes effective on July 23, 1986.