99-07-04: High Pressure Turbine (HPT) Disk

99-07-04 Williams International, L.L.C.: Amendment 39-11088. Docket 98-ANE-36-AD. Applicability: Williams International, L.L.C. FJ44-1A turbofan engines, installed on but not limited to Cessna 525 series aircraft. 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 (c) 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 high pressure turbine (HPT) disk rim failure, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) Prior to accumulating 1,900 cycles since new (CSN), remove from service HPT disk, part number (P/N) 55291, and replace with a serviceable part. (b) As an option to paragraph (a), modify the HPT nozzle assembly and remark the HPT disk and assembly with new P/Ns in accordance with Williams Rolls Service Bulletin (SB) FJ44-72-36, dated October 21, 1997. Note 2: The low cycle fatigue retirement lives for the HPT disks remarked with new P/Ns in accordance with paragraph (b) of this AD may be found in Williams Rolls SB FJ44-A-72-38, dated October 21, 1997. (c) 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, Chicago Aircraft 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, Chicago Aircraft Certification Office. Note 3: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago Aircraft Certification Office. (d) Thereafter, except as provided in paragraph (c) of this AD, no alternative replacement times or life limits may be approved for HPT disk, P/N 55291. (e) Special flight permits may be issued in accordance with sections 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. (f) The actions required by this AD shall be done in accordance with the following Williams Rolls SBs: Document No Pages Date FJ44-A-72-38 1-2 October 21, 1997 Total Pages: 2. FJ44-72-361-9 October 21, 1997 Total Pages: 9. 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 Williams Rolls, 2280 West Maple Road, P.O. Box 200, Walled Lake, MI 48390-0200; telephone (248) 960-2545, fax (248) 669-9515. 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. (g) This amendment becomes effective on May 24, 1999.