87-23-06 GENERAL ELECTRIC: Amendment 39-5746. Applies to General Electric (GE) CF6-50 and -45 series turbofan engines.
Compliance is required as indicated, unless already accomplished.
To prevent failure of the high pressure turbine (HPT) impeller spacer which may cause an uncontained engine failure, accomplish the following:
(a) Eddy current inspect impeller spacers part numbers (P/N's) 9190M82P02, PO3; 9234M25P01 through P04, inclusive; 9348M85P01; 9045M59P07, P08, P10, P12; 9173M55P01, P02, P03; and 9198M92P01 through P10, inclusive, in accordance with GE Service Bulletin (SB) 72-906, dated August 21, 1987, as follows:
(1) For HPT impeller spacers with 9,000 cycles since new (CSN) or greater on the effective date of this AD, inspect at the next shop visit or within 300 cycles in service (CIS) from the effective date of this AD, whichever occurs first.
(2) For HPT impeller spacers with 8,000 CSN or greater but less than 9,000 CSN on the effective dateof this AD, inspect at the next shop visit or within 600 CIS from the effective date of this AD, or prior to accumulating 9,300 CSN, whichever occurs first.
(3) For HPT impeller spacers with 7,000 CSN or greater but less than 8,000 CSN on the effective date of this AD, inspect at the next shop visit or within 900 CIS from the effective date of this AD or prior to accumulating 8,600 CSN, whichever occurs first.
(4) For HPT impeller spacers with 6,000 CSN or greater but less than 7,000 CSN on the effective date of this AD, inspect at the next shop visit or within 1,200 CIS from the effective date of this AD or prior to accumulating 7,900 CSN, whichever occurs first.
(5) For HPT impeller spacers with 2,500 CSN or greater but less than 6,000 CSN on the effective date of this AD, inspect at the next shop visit or within 2,000 CIS from the effective date of this AD or prior to accumulating 7,200 CSN, whichever occurs first.
(6) For HPT impeller spacers with less than2,500 CSN on the effective date of this AD, inspect at the next shop visit or prior to accumulating 4,500 CSN, whichever occurs first.
NOTE: Eddy current inspections of HPT impeller spacers completed prior to the effective date of this AD in accordance with GE SB 72-906, dated August 21, 1987, or with GE CF6-50/-45 Engine Shop Manual, Chapter 72-53-06, temporary revision 72-0593 are an alternate means of compliance with paragraph (a).
(b) Remove from service, HPT impeller spacers found cracked in accordance with the inspection requirements of paragraph (a) above and replace with a serviceable part.
(c) Reinspect impeller spacers, previously inspected in accordance with paragraph (a) above, at intervals not to exceed 2,500 cycles since last inspection in accordance with GE SB 72-906, dated August 21, 1987. Remove from service, impeller spacers found cracked and replace with a serviceable part.
(d) Remove, after October 30, 1990, impeller spacers listed by P/N's in this AD at the next shop visit or within 2,500 cycles since last inspection, whichever occurs first.
NOTE: Shop visit is defined as any time the high pressure turbine module is disassembled to a state where the impeller spacer is exposed.
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.
Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Manager, Engine Certification Office, New England Region, may adjust the compliance times specified in this AD.
General Electric SB 72-906, dated August 21, 1987, 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 General Electric, 1 Neumann Way, Cincinnati, Ohio 45215. This document also may be examined in the Office of the Regional Counsel, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803, Room 311, Rules Docket Number 87-ANE-30, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday, except federal holidays.
This amendment becomes effective on November 5, 1987.