AD 92-21-05

92-21-05 GARRETT AUXILIARY POWER DIVISION: Amendment 39-8385. Docket No. 92-NM-94-AD.

Applicability: Garrett Model GTCP 36-300 auxiliary power units (APU), as installed in, but not limited to, Airbus Industrie Model A320 series airplanes; Garrett Model GTCP 36-280(D) APU's, serial numbers prior to P-80346, as installed in, but not limited to, McDonnell Douglas Model DC-9-80 series airplanes; and Garrett Model GTCP 36-280(B) APU's, serial numbers prior to P-40182, as installed in, but not limited to, Boeing Model 737 series airplanes; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent damage to the titanium APU fire wall due to APU tieshaft separation, which could lead to a reduction in the fire protection capability of the APU compartment, accomplish the following:

(a) For airplanes equipped with Garrett Model GTCP 36-300 APU's: Within 30 months after the effective date of this AD, modify the APU, in accordance with Garrett Service Bulletin GTCP36-49-A6642, dated May 1, 1992.

(b) For airplanes equipped with Garrett Model GTCP 36-280 APU's: Within 30 months after the effective date of this AD, modify the APU, in accordance with Garrett Service Bulletin GTCP36-49-A6653, dated May 1, 1992.

(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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

(d) 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.

(e) The modification shall be done in accordance with either Garrett Service Bulletin GTCP36-49-A6642, dated May 1, 1992, or Garrett Service Bulletin GTCP36-49-A6653, dated May 1, 1992, as applicable. 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 Garrett Airlines Services Division, Technical Publications, Department 65-70, P.O. Box 52170, Phoenix, Arizona 85072-2170. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at FAA, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on November 24, 1992.