91-24-01 GENERAL ELECTRIC COMPANY: Amendment 39-8086. Docket No. 91-ANE-43. Supersedes AD 90-24-12, Amendment 39-6808.
Applicability: General Electric Company (GE) CF6-6 series turbofan engines installed on but not limited to McDonnell-Douglas DC-10 aircraft.
Compliance: Required as indicated, unless accomplished previously.
To prevent rupture of the compressor rear frame (CRF) casing that could result in an engine shutdown, aircraft damage, and aborted takeoff, accomplish the following:
(a) At the next scheduled open cowl check, but not later than 100 cycles in service (CIS) after the effective date of this AD, inspect the CRF outer case compressor discharge pressure (CDP) manifold port plug weld area for cracks in accordance with GE CF6-6 Service Bulletin (SB) 72-971, Revision 2, dated August 27, 1991.
(b) Remove from service, prior to further flight, CRF casings which exceed the serviceable limits specified in Table 1 or Table 2, as applicable, of GE CF6-6 SB 72-971, Revision 2, dated August 27, 1991.
(c) For engines with CRF casings inspected after December 11, 1990 (the effective date of AD 90-24-12), reinspect and remove from service CRF casings in accordance with the inspection intervals and crack limits specified in Table 1 of GE CF6-6 SB 72-971, dated October 2, 1990, until the first scheduled inspection after the effective date of this AD.
(d) Thereafter, reinspect and remove from service CRF casings in accordance with the inspection intervals and crack limits specified in Table 1 or Table 2, as applicable, of GE CF6-6 SB 72-971, Revision 2, dated August 27, 1991.
(e) At the next shop visit, but not later than 4,500 CIS after the effective date of this AD, perform a visual, fluorescent-penetrant, and radiographic inspection of the CRF, and rework the CRF in accordance with GE CF6-6 SB 72-977, dated March 15, 1991.
(f) For the purpose of this AD, a shop visit is defined as the CRF exposed at the piece-part level.
(g) Compliance with paragraph (e) of this AD eliminates the inspection requirements of paragraphs (a), (b), (c), and (d) of this AD and constitutes a terminating action to this AD.
(h) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Engine Certification Office, ANE-140, Engine and Propeller Directorate, Aircraft Certification Service, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Engine Certification Office.
(i) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.
(j) The reinspections and removal of CRF casings shall be done in accordance with General Electric CF6-6 Service Bulletin 72-971, dated October 2, 1990. This incorporation by reference was previously approved by the Director of the Federal Register at 55 FR 48591, (December 11, 1990) in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies of General Electric service bulletins may be obtained from General Electric Aircraft Engines, Technical Publications Department, 1 Neumann Way, Cincinnati, Ohio 45215. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Room 311, Burlington, Massachusetts, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C.
(k) The inspections and rework shall be done in accordance with the following General Electric Company documents:
Document Number
Page Number
Issue/Rev
Date
GE CF6-6 SB 72-971
1-11
Revision 2
8/27/91
12
Original
10/2/90
Total: 12 pages
GE CF6-6 SB 72-977
1-34
Original
3/15/91
Total: 34 pages
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 of General Electric service bulletins may be obtained from General Electric Aircraft Engines, Technical Publications Department, 1 Neumann Way, Cincinnati, Ohio 45215. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Room 311, Burlington, Massachusetts, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C.
(l) This amendment becomes effective on May 26, 1992.