# AD 92-21-05: Auxiliary Power Units - Type: Airworthiness directive - Status: Current - Products: Airbus A320-111, A320-211, A320-212, A320-214, A320-231, A320-232, A320-233, 737-100 Series, 737-200 Series, 737-200C Series, 737-300 Series, 737-400 Series and 11 more - Effective: November 24, 1992 - Superseded by: Nothing supersedes this AD - Product type: Appliance - Amendment: 39-8385 - Docket: 92-NM-94-AD - Registered aircraft: 1,484 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E39955EA395A5BF286256A3E00765F13.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/92-21-05 ## The airworthiness directive 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. ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 11 of 17 models: 737-500 Series, 737-900 Series, 737-100 Series, 737-200C Series, 737-700C Series, 737-800 Series, 737-300 Series, 737-200 Series… - [TCDS A28NM](https://openairdocs.org/tcds/A28NM): Airbus SAS; names 7 of 50 models: A320-111, A320-211, A320-212, A320-214, A320-231, A320-232, A320-233 - [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 4 of 25 models: DC-9-81 (MD-81), DC-9-83 (MD-83), DC-9-87 (MD-87), DC-9-82 (MD-82) ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 1,484 (1,484 by airframe model, 0 by engine model) - Makers: Boeing 835, Airbus 377, Airbus Industrie 184, Mcdonnell Douglas 85, Airbus S A S 2, Douglas 1 Models with the most aircraft: - [Boeing 737-823](https://openairdocs.org/model/boeing-737-823): 278 aircraft (airframe model) - [Airbus A320-232](https://openairdocs.org/model/airbus-a320-232): 188 aircraft (airframe model) - [Airbus A320-214](https://openairdocs.org/model/airbus-a320-214): 160 aircraft (airframe model) - [Boeing 737-800](https://openairdocs.org/model/boeing-737-800): 139 aircraft (airframe model) - [Boeing 737-824](https://openairdocs.org/model/boeing-737-824): 135 aircraft (airframe model) - [Airbus Industrie A320-232](https://openairdocs.org/model/airbus-industrie-a320-232): 109 aircraft (airframe model) - [Boeing 737-832](https://openairdocs.org/model/boeing-737-832): 73 aircraft (airframe model) - [Boeing 737-890](https://openairdocs.org/model/boeing-737-890): 60 aircraft (airframe model) - [Mcdonnell Douglas DC-9-83(MD-83)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-83-md-83): 49 aircraft (airframe model) - [Airbus Industrie A320-212](https://openairdocs.org/model/airbus-industrie-a320-212): 39 aircraft (airframe model) - [Boeing 737-724](https://openairdocs.org/model/boeing-737-724): 36 aircraft (airframe model) - [Airbus Industrie A320-214](https://openairdocs.org/model/airbus-industrie-a320-214): 26 aircraft (airframe model) - [Mcdonnell Douglas DC-9-82(MD-82)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-82-md-82): 22 aircraft (airframe model) - [Airbus A320-233](https://openairdocs.org/model/airbus-a320-233): 21 aircraft (airframe model) - [Boeing 737-790](https://openairdocs.org/model/boeing-737-790): 14 aircraft (airframe model) - [Boeing 737-752](https://openairdocs.org/model/boeing-737-752): 13 aircraft (airframe model) - [Mcdonnell Douglas DC-9-87](https://openairdocs.org/model/mcdonnell-douglas-dc-9-87): 13 aircraft (airframe model) - [Boeing 737-924](https://openairdocs.org/model/boeing-737-924): 12 aircraft (airframe model) - [Boeing 737-400](https://openairdocs.org/model/boeing-737-400): 8 aircraft (airframe model) - [Boeing 737-852](https://openairdocs.org/model/boeing-737-852): 7 aircraft (airframe model) All 61 models: https://openairdocs.org/ad/92-21-05/models.md Every aircraft: https://openairdocs.org/ad/92-21-05/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.