AD 96-18-17 Airworthiness Directives; AlliedSignal Inc. TSCP700-4B, -4E, and -5 Auxiliary Power Units

AlliedSignal Inc. (formerly Garrett) Models TSCP700-4B, -4E, and -5 auxiliary power units (APUs), with high pressure turbine (HPT) disks identified by serial number in AlliedSignal Aerospace Service Bulletin (SB) No. TSCP700-49-A7168, dated November 7, 1995. These APUs are installed on, but not limited to, McDonnell Douglas DC-10, KC-10 (military), and MD-11 series, and Airbus A300 series aircraft. Note: This airworthiness directive (AD) applies to each APU 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 APUs 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 (d) 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.

Required as indicated, unless accomplished previously. To prevent an HPT disk rupture, accomplish the following: (a) Prior to accumulating 7,500 cycles since new (CSN), or 3 years after the effective date of this AD, whichever occurs first, remove from service affected HPT disks and replace with a serviceable part. (b) The definition of a disk cycle may be found in the applicable AlliedSignal Inc. APU Component Maintenance Manual. (c) Auxiliary power unit maintenance records may be used to determine if the HPT disk installed in the APU has a serial number listed in AlliedSignal Aerospace SB No. TSCP700-49-A7168, dated November 7, 1995. (d) 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, Los Angeles Aircraft 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, Los Angeles Aircraft Certification Office. Note: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Los Angeles Aircraft Certification Office. (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 AlliedSignal Aerospace SB: ------------------------------------------------------------------------ Document No. Pages Date ------------------------------------------------------------------------ TSCP700-49-A7168..................... 1-8 Nov. 7, 1995. Total Pages: 8. ------------------------------------------------------------------------ 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 AlliedSignal Engines, P.O. Box 52181, Phoenix, AZ 85072-2181; telephone (800) 338-3378, fax (602) 231-4402. 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. (g) This amendment becomes effective on December 9, 1996. Issued in Burlington, Massachusetts, on September 20, 1996. James C. Jones, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 96-25168 Filed 10-8-96; 8:45 am] BILLING CODE 4910-13-U