2001-10-03: Fan Disks

2001-10-03 General Electric Company: Amendment 39-12229. Docket 2000-NE-42-AD. Applicability This airworthiness directive (AD) is applicable to General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines with fan disk part numbers (P/N's) 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06 installed. These engines are installed on but not limited to Bombardier, Inc. Canadair airplane models CL-600-2A12, -2B16, and -2B19. Note 1: This 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 (e) 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 Compliance with this AD is required as indicated, unless already done. To prevent rupture of the fan disk due to cracks that initiate at an electrical arc-out, which could result in an uncontained failure of the engine, do the following: Removal of Certain Fan Disks from Service (a) On disk P/N's 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06, that are listed by P/N and serial number (SN) in the following Table 1 of this AD and that have less than 8,000 cycles-since-new (CSN) on the effective date of this AD, replace fan disk P/N's before accumulating 8,000 CSN: Table 1. Fan Disks That Require Removal Based on Blended Callouts Disk part number Disk serial number 6078T57G04 GEE09287 6078T00G01 GAT3860G 6078T57G02 GAT1924L 5922T01G04 GAT9599G 6078T57G04 GEE05831 6078T57G04 GEE06612 6078T57G04 GEE06618 6078T57G04 GEE06974 6078T57G04 GEE06980 6078T57G05 GEE143FY 6078T57G05 GEE1453G 6078T57G05 GEE14452 6078T57G05 GEE145NA 6078T57G04 GEE08086 6078T57G04 GEE09287 6078T57G04 GEE09337 6078T57G05 GEE12720 6078T57G05 GEE14214 6078T57G05 GEE142YT 6078T57G05 GEE146GT (b) For disks with SN's listed in Table 1 of this AD that have 8,000 CSN or greater on the effective date of this AD, replace the disk within 30 days after the effective date of this AD. Inspection of All Other Fan Disks (c) Inspect all other fan disks, P/N's 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06 in accordance with paragraphs 3.A.(1) through 3.E.(2) of the Accomplishment Instructions of Alert Service Bulletin (ASB) CF34-BJ 72-A0088, Revision 1, dated October 30, 2000 or paragraphs 3.A.(1) through 3.A.(2)(f) of the Accomplishment Instructions of ASB CF34-AL 72-A0103, dated August 4, 2000. Use the compliance times specified in the following Table 2: Table 2. Fan Disk Inspection Compliance Times Fan disk operating CSN Inspect by (1) Fewer than 8,000 CSN on the effective date of this AD. Before accumulating 8,000 CSN or by the next hot section inspection after the effective date of this AD, whichever occurs earlier. (2) 8,000 CSN or greater on the effective date of this AD. Within 120 days after the effective date of this AD. Definitions (d) For the purposes of this AD, the following definitions apply: (1) Aserviceable fan disk is defined as a fan disk that has been inspected as specified in paragraph (c) of this AD and is not listed in Table 1 of this AD. (2) Cycles-since-new for fan disk P/N's 5922T01G04 or 5922T01G05 is defined as total cycles accrued since new as P/N 6078T57G02 or 6078T57G03, added to total cycles accrued after modification from P/ N 6078T57G02 or 6078T57G03. Alternative Methods of Compliance (e) 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 (ECO). Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO. Special Flight Permits (f) Special flight permits may be issued in accordance with Secs. 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. Documents That Have Been Incorporated by Reference (g) The actions specified in this AD must be done in accordance with the following GE alert service bulletins: Document No. Pages Revision Date ASB CF34-BJ 72-A0088 Total pages: 15 All 1 October 30, 2000. ASB CF34-AL 72-A0103 Total pages: 78 All Original August 4, 2000. These incorporations by reference were 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 GE Aircraft Engines, 1000 Western Avenue, Lynn, MA 01910; Attention: CF34 Product Support Engineering, Mail Zone: 34017; telephone (781) 594-6323; fax (781) 594-0600. Copies may be inspected at the FAA, New England Region, Office of the RegionalCounsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Effective Date of This AD (h) This amendment becomes effective on May 31, 2001.