AD 91-25-04

91-25-04 GARRETT AUXILIARY POWER DIVISION: Amendment 39-8105. Docket No. 91-NM-151-AD.

Applicability: Model TSCP700-4B auxiliary power units (APU) prior to serial number 90697, as installed in, but not limited to, McDonnell Douglas Model DC-10 and KC-10 (military) series airplanes; and Model TSCP700-5 APU's prior to serial number 80443, as installed in, but not limited to, Airbus Industrie Model A300 series airplanes; certificated in any category.

Compliance: Required within 24 months after the effective date of this AD, unless previously accomplished.

To prevent uncontained high pressure turbine (HPT) disc failures, accomplish the following:

(a) Replace the HPT containment ring, part number (P/N) 976850-1, with P/N 3614975-1; and replace the HPT containment support, P/N 3604274-1, with P/N 3614934-1; in accordance with the accomplishment instructions in Garrett Service Bulletin TSCP700-49-5892, Revision 2, dated October 10, 1990.

(b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(d) The replacement requirements shall be done in accordance with Garrett Service Bulletin TSCP700-49-5892, Revision 2, dated October 10, 1990, which contains the following list of effective pages:

Page Number Revision Level Date 1, 7/8 2 October 10, 1990 2, 3/4, 5, 6 Original) May 14, 1990 9/10 1 July 3, 1990

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, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

This amendment (39-8105, AD 91-25-04) becomes effective on January 7, 1992.