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93-14-14
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Compressor Fan Hub Category
- Engine Applicability: Pratt & Whitney (PW) Model JT8D-9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines containing front compressor fan hub Part Number (P/N) 817401 with the following serial numbers: J78892 through J80538, K32019 through K34018, L32197 through L34133, or M05722 through M07296; and all serial numbers of fan hubs P/N 594301, 640601, 743301, 749801, 750101, 791801, and 806001. These engines are installed on but not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 series aircraft. Compliance: Required as indicated, unless accomplished previously. To prevent fracture of the front compressor fan hub, which can result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) For front compressor fan hubs installed in engines in the No. 2 position on Boeing 727 aircraft on the effective date of this AD, or thereafter, inspect and shotpeen the front compressor fan hub in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW Alert Service Bulletin (ASB) No. 6104, Revision 2, dated June 18, 1993, as follows: (1) Initially inspect the front compressor fan hub as follows: Total Part Cycles (TPC) on the effective date Initial of this AD Inspection Interval Over 18,001 TPC Inspect at the next shop visit, or within 300 cycles in service (CIS) after the effective date of this AD, whichever occurs first. 16,501 to 18,000 TPC Inspect at the next shop visit, or within 500 CIS after the effective date of this AD, whichever occurs first. 15,001 to 16,500 TPC Inspect at the next shop visit, or within 750 CIS after the effective date of this AD, whichever occurs first. visit, or within 1,000 CIS after the effective date of this AD, whichever occurs first. 10,501 to 13,500 TPC Inspect at the next shop visit, or within 1,500 CIS after the effective date of this AD, whichever occurs first. Less than 10,501 TPC Inspect at the next shop visit after accumulating 10,500 TPC, but not to exceed 12,000 TPC. (2) Engines may be removed from the No. 2 position on Boeing 727 aircraft and reinstalled in any position other than the No. 2 position on Boeing aircraft prior to reaching the initial inspection interval specified in paragraph (a)(1) of this AD. Inspect and shotpeen front compressor fan hubs on repositioned engines in accordance with paragraph (b) of this AD. (3) Remove front compressor fan hubs from service if cracks are found during the inspection process and replace with a serviceable hub. (4) Shotpeen the front compressor fan hubs that pass the inspections required by paragraph (a)(1) of this AD, in accordance with Appendix B of PW ASB No. 6104, Revision 2, dated June 18, 1993, prior to returning the hub to service. (5) Thereafter, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are reinstalled in the No. 2 position of Boeing 727 aircraft, in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764), as applicable, of PW ASB No. 6104, Revision 2, dated June 18, 1993, as follows: (i) For hubs that were last inspected and shotpeened with greater than 12,000 TPC upon inspection, inspect and shotpeen at the first shop visit after 2,500 CIS since last inspection, but prior to the accumulation of 8,000 CIS since last inspection. (ii) For hubs that were last inspected and shotpeened with less than or equal to 12,000 TPC upon inspection, inspect and shotpeen at the first shop visit after 2,500 CIS since last inspection, or prior to accumulating 12,000 TPC, whichever occurs later, but not to exceed 8,000 CIS since last inspection. (6) Engines may be removed from the No. 2 position on Boeing 727 aircraft and reinstalled in any position other than the No. 2 position on Boeing 727 aircraft prior to reaching the repetitive inspection interval specified in paragraph (a)(5) of this AD. Inspect and shotpeen front compressor fan hubs on repositioned engines in accordance with paragraph (b)(4) of this AD. (b) For front compressor fan hubs installed in engines that are installed in any position other than the No. 2 position on Boeing 727 aircraft on the effective date of this AD, or thereafter, inspect and shotpeen the front compressor fan hubs in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. 6104, Revision 2, dated June 18, 1993, as follows: (1) Initially inspect the front compressor fan hub at the next shop visit that occurs after 12,000 TPC. (2) Remove front compressor fan hubs from service if cracks are found during the inspection process and replace with a serviceable hub. (3) Shotpeen the front compressor fan hubs that pass the inspection requirements specified in paragraph (b)(1) of this AD, in accordance with Appendix B of PW ASB No. 6104, Revision 2, dated June 18, 1993, prior to returning the hub to service. (4) Thereafter, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are not reinstalled in the No. 2 position on Boeing 727 aircraft, in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. 6104, Revision 2, dated June 18, 1993, when the front compressor fan hub is accessible at the detail level in the shop, or within 2,500 CIS since last inspection, whichever occurs later. (5) Thereafter, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are reinstalled in the No. 2 position of Boeing 727 aircraft after the effective date of this AD in accordance with paragraph (a)(5) of this AD. (c) Inspect and shotpeen front compressor fan hubs that were inspected and shotpeened prior to the effective date of this AD in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. 6104, dated December 21, 1992, or PW ASB No. 6104, Revision 1, dated May 21, 1993, in accordance with paragraphs (a)(5) or (b)(4) of this AD, as applicable. (d) For the purpose of this AD, a shop visit is defined as an engine removal where engine maintenance entails separation of pairs of mating engine flanges or the removal of a disk, hub, or spool. (e) For the purpose of this AD, accessibility of a front compressor fan hub at the detail level in the shop is defined as engine maintenance that entails separation of the front compressor fan hub from the front compressor and removal of the fan blades. (f) Report the front compressor fan hub part number, total time, and total cycles in service for each hub that passes the inspections defined in this AD, within 60 days after the inspection, to the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, FAA, 12 New England Executive Park, Burlington, Massachusetts, 01803-5299; fax (617) 238-7140; Telex 949301 FAANE BURL. For any hub that is found cracked, submit the information requested in paragraph B of Part 4, of the Accomplishment Instructions of PW ASB No. 6104, Revision 2, dated June 18, 1993, within 60 days after the inspection to the Manager, Engine Certification Office, at the address identified above. The reporting requirements of this AD terminate one year after the effective date of this AD. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provision of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501-3520) and have been assigned OMB Control Number 2120-0056. (g) 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. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. (h) 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. (i) The inspections and shotpeening shall be done in accordance with the following PW ASB: ASB No. Pages Revision Date PW ASB No. 6104 1 2 June 18, 1993 2 and 3 1 May 21, 1993 4 2 June 18, 1993 5 and 6 1 May 21, 1993 7 2 June 18, 1993 8 thru 13 1 May 21, 1993 with Attachment 1-13 Original December 8, 1992 No. NDIP-764 Total pages: 26 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 Pratt & Whitney, Technical Publications Department, M/S 132-30, 400 Main Street, East Hartford, CT 06108. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief 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. (j) This amendment becomes effective on August 10, 1993. FOR FURTHER INFORMATION CONTACT: Mark A. Rumizen, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7137, fax (617) 238-7199.
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