2000-11-12 General Electric Company: Amendment 39-11760. Docket 98-ANE-32-AD.
Applicability: General Electric Company (GE) Model CF6-45/50 series turbofan engines, installed on but not limited to Airbus Industrie A300 series, Boeing Company 747 series, and McDonnell Douglas Corporation DC-10 series airplanes
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (j) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent a stage 14 high pressure compressor (HPC) disk failure, which could result in uncontained engine failure and damage to the aircraft, accomplish the following:
Inspections
(a) Perform initial inspections of HPC stage 14 disks, part numbers (P/N's) 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04, with serial number (SN) prefixes GWN, MPO, RRY, and SNL, and disk SN's SNE00001 through SNE00017, and disk SN's SNE01101 through SNE01110, in accordance with paragraphs 2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) Inspect disks with 6,500 cycles since new (CSN) or less on the effective date of this AD before accumulating 9,800 CSN.
(2) Inspect disks with more than 6,500 CSN on the effective date of this AD no later than the next engine shop visit (ESV) after the effective date of this AD or before accumulating an additional 3,300 cycles- in-service (CIS) after the effective date of this AD, whichever occurs first.
(b) Perform repetitive inspections of HPC stage 14 disks, P/N's 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04, with SN prefixes GWN, MPO, RRY, and SNL, and disk SN's SNE00001 through SNE00017, and disk SN's SNE01101 through SNE01110, in accordance with paragraphs 2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) For disks with less than 9,800 CSN at the time of the last inspection, perform repetitive inspections no later than 9,800 CSN or before accumulating 3,300 cycles since last inspection (CSLI), whichever occurs later.
(2) For disks with 9,800 CSN or greater at the time of the last inspection, perform repetitive inspections no later than 3,300 CSLI.
(c) Performinitial inspections of HPC stage 14 disks, P/N's 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes SNG and SNE, except disk SN's SNE00001 through SNE00017 and SNE01101 through SNE01110, in accordance with paragraphs 2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) Inspect disks with 4,200 CSN or less on the effective date of this AD before accumulating 7,500 CSN.
(2) Inspect disks with more than 4,200 CSN but less than 9,000 CSN on the effective date of this AD at the next ESV after the effective date of this AD, before accumulating an additional 3,300 CIS after the effective date of this AD, or before accumulating 11,000 CSN, whichever occurs first.
(3) Inspect disks with 9,000 CSN or greater on the effective date of this AD, at the next ESV after the effective date of this AD, or before accumulating an additional 2,000 CIS after the effective date ofthis AD, whichever occurs first.
(d) Perform repetitive inspections of HPC stage 14 disks, P/N's 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes SNG and SNE, except disk SN's SNE00001 through SNE00017 and SNE01101 through SNE01110, in accordance with paragraphs 2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) For disks with less than 7,500 CSN at the time of the last inspection, perform repetitive inspections no later than 7,500 CSN or before accumulating 3,300 CSLI, whichever occurs later.
(2) For disks with 7,500 CSN or greater at the time of the last inspection, perform repetitive inspections no later than 3300 CSLI.
Removal from Service
(e) Remove from service prior to further flight stage 14 HPC disks that equal or exceed the reject criteria established by GE CF6-50 ASB 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, datedMay 13, 1999.
(f) Remove from service, HPC stage 14 disks, P/N's 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes SNG and SNE, except disk SN's SNE00001 through SNE00017 and SNE01101 through SNE01110, with greater than 6,000 CSN after the effective date of this AD, at the next piece-part level exposure or at the next HPC rotor disassembly level exposure after the effective date of this AD.
Terminating Action
(g) Replacement of the stage 14 HPC disk, P/N's 9080M34P03, 9080M34P04, 9080M34P05, 9349M91P04, with a stage 11 - 14 spool shaft is terminating action for the inspection requirements of this AD.
Reporting Requirements
(h) Report the results of inspections that equal or exceed the reject criteria within five days of the inspection to: Manager, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299, telephone, (781) 238-7141, fax, (781) 238-7199. The following information must be included in the report:
(1) HPC Stage 14 rotor disk P/N,
(2) HPC Stage 14 rotor disk SN,
(3) HPC Stage 14 rotor disk CSN,
(4) HPC Stage 14 rotor disk CSLI, and
(5) Date and location of inspection.
Reporting requirements have been approved by the Office of Management and Budget (OMB) and assigned OMB control number 2120-0056.
Definitions
(i) For the purpose of this AD, the following definitions apply:
(1) HPC Rotor disassembly occurs if any of the HPC Rotor bolted flange joints are separated, such as the Stage 2 joint to accomplish the Stage 3-9 Spool inspection.
(2) Piece-part exposure is defined as disassembly and removal of the stage 14 disk from the HPC rotor structure, regardless of any blades, locking lugs, bolts or balance weights assembled to the disk.
(3) An engine shop visit is defined as the introduction of an engine into a shop when a major engine flange is separated. The following maintenance actions are not considered engine shop visitsfor the purpose of this AD:
(i) Introduction of an engine into a shop solely for removal or replacement of the Stage 1 Fan Disk;
(ii) Introduction of an engine into a shop solely for replacement of the Turbine Rear Frame;
(iii) Introduction of an engine into a shop solely for replacement of the Accessory Gearbox or Transfer Gearboxes;
(iv) Introduction of an engine into a shop solely for replacement of the Fan Forward Case.
(v) Introduction of an engine into a shop for any combination of exceptions specified in paragraphs (i)(3)(i) through (i)(3)(iv);
Alternative Methods of Compliance
(j) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
Incorporation by Reference
(k) The inspections shall be done in accordance with paragraphs 2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, 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 Company via Lockheed Martin Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone (513) 672-8400, fax (513) 672-8422. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the
Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.
Special Flight Permit
(l) Special flight permits may be issued in accordance with 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.
Effective Date of This AD
(m) This amendment becomes effective on August 14, 2000.