AD 91-05-21 ACTIVE

91-05-21 GENERAL ELECTRIC COMPANY: Amendment 39-6900. Docket No. 90-ANE- 28. Applicability: General Electric Company (GE) CF6-80C2A5 and CF6-80C2B6 engines, Serial Numbers (S/N) 690-101 through 690-369, and S/N 695-101 through 695-423; and CF6- 80C2B6F and CF6-80C2D1F engines, S/N 702-101 through 702-470, and S/N 703-101 through 703-136, which do not incorporate the increased shroud cooling design features of paragraph (b) of this AD, installed on, but not limited to, Airbus A300, Boeing 767, and McDonnell Douglas MD-11 aircraft.
Compliance: Required as indicated, unless previously accomplished.
To prevent high pressure turbine (HPT) failure and possible aircraft damage, accomplish the following:
(a) Borescope inspect engines in accordance with sections 2.B., 2.C., and 2.D of the Accomplishment Instructions in GE CF6-80C2 Service Bulletin (SB) 72-473, Revision 1, dated September 21, 1990, unless previously accomplished, according to the following schedule based upon cycles since new (CSN) on the effective date of this AD:
(1) Inspect within 10 cycles in service (CIS) after the effective date of this AD or prior to accumulating 520 CSN, whichever occurs later, for CF6-80C2A5 and CF6- 80C2B6 engines, S/N 690-101 through 690-369, and S/N 695-101 through 695-350; and CF6- 80B6F engines, S/N 702-101 through 702-315, and S/N 702-317 through 702-321.
(2) Inspect within 10 CIS after the effective date of this AD or prior to accumulating 1,250 CSN, whichever occurs later, for CF6-80C2A5 and CF6-80C2B6 engines, S/N 695-351 through 695-423; and CF6-80C2B6F and CF6-80C2D1F engines, S/N 702-316, 702-322 through 702-470, and S/N 703-101 through 703-136.
(3) Remove from service or reinspect in accordance with the following:
(i) Remove from service prior to further flight, engines with at least one Category 4 shroud.
(ii) Remove from service within 25 hours time in service (TIS) since last inspection (SLI), engines with no Category 4 shrouds, but at least one Category 3 shroud.
(iii) Borescope reinspect at intervals not to exceed 125 hours TIS SLI, engines with no Category 3 or 4 shrouds, but at least one Category 2 shroud.
(iv) Borescope reinspect at intervals not to exceed 300 hours TIS SLI, engines with no Category 2,3, or 4 shrouds, but at least one Category 1 shroud.
(v) Borescope reinspect at intervals not to exceed 520 CIS SLI, engines with no Category 1, 2, 3, or 4 shrouds.
(b) Replace the HPT stator stage one shroud support assemblies, Part Numbers (P/N) 9381M61G06 and 9381M61G07; the HPT stator support hanger assemblies, P/N 9397M73G05 and 9397M73G06; and the HPT stage one shrouds, P/N 1333M75P05, 1333M75P06, 1333M75P07, 1333M75P08, 1333M75P09, and 1333M75P10 in accordance with the Accomplishment Instructions in GE CF6-80C2 SB 72-474, Revision 1, dated December 11, 1990, at the next HPT module exposure after the effective date of this AD, but prior to December 31, 1994.
(c) For the purpose of this AD, HPT module exposure is defined as the separation of the HPT stator support case from the compressor rear frame.
(d) For the purpose of this AD, the shroud Categories are defined in GE CF6-80C2 SB 72-473, Revision 1, dated September 21, 1990.
(e) 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.
(f) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance times specified in this AD may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803-5299.
The borescope inspections and installation of improved HPT hardware shall be done in accordance with the following documents:

Document
Page
Revision
Date
CF6-80C2SB 72-473
5, 6, 7,
Original
7/3/90

10-23

1, 2, 3,
Rev. 1
9/21/90

4, 8, and 9

CF6-80C2 SB 72-474
1-24
Rev. 1
12/11/90

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from General Electric Aircraft Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street, Cincinnati, Ohio 45246. Copies may be inspected at the Office of the Assistant Chief Counsel, FAA, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts, or at the Office of the Federal Register, 1100 L Street, NW, Room 8401, Washington, DC.
This amendment (39-6900, AD 91-05-21) becomes effective on March 27, 1991.