# AD 97-04-04: Auxiliary Power Units - Type: Airworthiness directive - Status: Current - Products: Airbus BAC 1-11 200 Series, BAC 1-11 400 Series, Auxiliary Power Units, 707-100 Long Body, 707-100B Long Body, 707-100B Short Body, 707-200, 707-300 Series, 707-300B Series, 707-300C Series, 707-400 Series, 727-100 Series and 45 more - Effective: March 24, 1997 - Published: February 21, 1997, 62 FR 7932–7934 - Issued: February 4, 1997 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Appliance - Amendment: 39-9927 - Docket: 96-ANE-15 - Registered aircraft: 984 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/83/14/8314beac623877a661af4922c81f7abe136a37f549f7ec323a8a997aeea203ab (from https://www.govinfo.gov/content/pkg/FR-1997-02-21/pdf/97-4098.pdf) - Federal Register: https://www.federalregister.gov/documents/1997/02/21/97-4098/airworthiness-directives-alliedsignal-inc-gtcp85-series-auxiliary-power-units - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9FDC6F3B774DB8CF8625697700649706.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/97-04-04 ## Summary This amendment supersedes an existing airworthiness directive (AD), applicable to AlliedSignal Inc. (formerly Garrett Auxiliary Power Division) GTCP85 Series auxiliary power units (APUs), that currently requires removing the existing turbine wheel shroud and installing one constructed of Hastelloy "S" material, or installing a containment augmentation ring. This amendment deletes the option of installing a turbine shroud constructed of Hastelloy "S" material. This amendment is prompted by a report of insufficient APU containment capability with the Hastelloy "S" shroud alone installed. The actions specified by this AD are intended to prevent turbine shroud fragments from exiting the APU and puncturing the APU compartment, which could result in reduced fire extinguishing capability in the APU compartment. ## The airworthiness directive 97-04-04 AlliedSignal Inc.: Amendment 39-9927. Docket 96-ANE-15. Supersedes AD 93-07-13, Amendment 39-8545. Applicability: AlliedSignal Inc. (formerly Garrett Auxiliary Power Division) GTCP85 series auxiliary power units (APUs), incorporating a one-piece cast turbine wheel, Part Numbers (P/Ns) 968095-X, 3604604-X, 3606982-1, or 3842072-X (where "X" denotes any number). These APUs are installed on but not limited to the following aircraft: British Aerospace BAC 1-11 series; Boeing 707, 727, and 737 series; Lockheed 382 series; and McDonnell Douglas DC-8-70, DC-9, and MD-88 series aircraft. Note 1: 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 (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 turbine shroud fragments from exiting the APU and puncturing the APU compartment, which could result in reduced fire extinguishing capability in the APU compartment, accomplish the following: (a) For flight operable APUs, within 24 months after the effective date of this AD, accomplish either of the following: (1) Install a containment augmentation ring, P/N 3616426-3, in accordance with AlliedSignal Aerospace Alert Service Bulletin (ASB) No. GTCP85-49-A7189, Revision 2, dated October 8, 1996, Revision 1, dated July 19, 1996, or Original, dated March 29, 1996; or (2) Install a containment augmentation ring, P/N 3616426-1, in accordance with AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 2, dated November 28, 1994, AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 1, dated November 12, 1993, or Garrett ASB No. GTCP85-49-A6706, Original, dated December 7, 1992. (b) For APUs that are operable on the ground only, within 36 months after the effective date of this AD, accomplish either of the following: (1) Install a containment augmentation ring, P/N 3616426-3, in accordance with AlliedSignal Aerospace ASB No. GTCP85-49-A7189, Revision 2, dated October 8, 1996, Revision 1, dated July 19, 1996, or Original, dated March 29, 1996; or (2) Install a containment augmentation ring, P/N 3616426-1, in accordance with AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 2, dated November 28, 1994, AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 1, dated November 12, 1993, orGarrett ASB No. GTCP85-49-A6706, Original, dated December 7, 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. 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 2: Information concerning the existence of approved alternative method of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office. (d) 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. (e) The actions required by this AD shall be done in accordance with the following ASBs:Document No. Pages Revision Date AlliedSignal Aerospace GTCP85-49-A7189 1-14 2 October 8, 1996 Total pages: 14. AlliedSignal Aerospace GTCP85-49-A7189 1-12 1 July 19, 1996 Total pages: 12. AlliedSignal Aerospace GTCP85-49-A7189 1-10 Original March 29, 1996 Total pages: 10. AlliedSignal Aerospace GTCP85-49-A6706 1 2 November 28, 1994 2,3 1 November 12, 1993 4 2 November 28, 1994 5-8 1 November 12, 1993 9,10 2 November 28, 1994 Total pages: 10. AlliedSignal Aerospace GTCP85-49-A6706 1-10 1 November 12, 1993 1-10 1 November 12, 1993 1-10 1 November 12, 1993 Total pages: 10. Garrett GTCP85-49-A6706 1,2 Original December 7, 1992 4-10 Original December 7, 1992 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 AlliedSignal Aerospace, Attn: Data Distribution, M/S 64-3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax (602) 365-5577. 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. (f) This amendment becomes effective on March 24, 1997. ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-07-13, Amendment 39-8545 (58 FR 21917, April 26, 1993), which is applicable to AlliedSignal Inc. (formerly Garrett Auxiliary Power Division) GTCP85 Series auxiliary power units (APUs), was published in the Federal Register on August 12, 1996 (61 FR 41751). That action proposed to require installing an improved containment augmentation ring, Part Number (P/N) 3616426-1, or P/N 3616426-3, which is a redesigned containment augmentation ring to allow installation on certain APUs that cannot accept the -1 containment augmentation ring. The containment augmentation rings, P/Ns 3616426-1 and 3616426-3, improve the containment capability of the APU relative to the earlier containment augmentation ring, P/N 3612249-1, by preventing turbine shroud fragments from passing around the containment augmentation ring. The installation must be accomplished within 24 months after the effective date of this AD, for flight operable APUs, and within 36 months after the effective date of this AD, for APUs that are operable on the ground only. The actions would be required to be accomplished in accordance with AlliedSignal Aerospace Alert Service Bulletin (ASB) No. GTCP85- 49-A7189, Revision 2, dated October 8, 1996, AlliedSignal Aerospace ASB No. GTCP85-49-A7189, Revision 1, dated July 19, 1996, or AlliedSignal Aerospace ASB No. GTCP85-49-A7189, Original, dated March 29, 1996; and AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 2, dated November 28, 1994, AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 1, dated November 12, 1993, or Garrett ASB No. GTCP85-49-A6706, Original, dated December 7, 1992. Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. One commenter states that the AD should apply only to APUs with one-piece cast turbine wheels made of MAR-M-247 material, as only these type turbine wheels have failed in the commenter's experience. The FAA concurs in part. The proposed rule as written applies to APUs with one-piece cast turbine wheels with the listed P/Ns, which are made of MAR-M-247 material, but also Inconel, which have failed as well. Two commenters state that the AD should add an additional method of compliance by replacing the one-piece cast turbine wheels with two-piece wheels. The FAA does not concur. The proposed AD does not apply to APUs with two-piece turbine wheels. One commenter (the manufacturer) states that the economic analysis provides figures for the number of APUs in service domestically and worldwide that are too low. The FAA concurs and revised the economic analysis of this final rule accordingly. One commenter states that the proposed AD should be more clear in stating that compliance is acceptable with either ASB stated in paragraphs (a)(1) and (a)(2) and (b)(1) and (b)(2) of the compliance section. The FAA concurs and has put the "or" between the appropriate paragraphs in bold type to highlight its significance Two commenters concur with the AD as proposed. Since publication of the proposed rule, AlliedSignal Aerospace has issued Revision 2 to ASB No. GTCP85-49-A7189, dated October 8, 1996, which is referenced in this final rule along with Revision 1, dated July 19, 1996, and Original, dated March 29, 1996. These revisions of that ASB are all approved methods of compliance for the appropriate paragraphs of this AD. After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. There are approximately 4,100 APUs of the affected design in the worldwide fleet. The FAA estimates that 1,300 APUs installed on aircraft of U.S. registry will be affected by this AD, that it will take no additional work hours if the required actions are accomplished when the APU is already disassembled in the shop. Required parts will cost approximately $1,550 per APU. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,015,000. The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39 Air Transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 USC 106(g), 40113, 44701. § 39.13 - (AMENDED) 2. Section 39.13 is amended by removing Amendment 39-8545 (52 FR 45163, November 25, 1987) and by adding a new airworthiness directive, Amendment 39-9927, to read as follows: ## Affected data sheets (7) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 20 of 25 models: DC-9-12, DC-9-15F, MD-88, DC-9-41, DC-9-13, DC-9-34F, DC-9-81 (MD-81), DC-9-33F… - [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 4A25](https://openairdocs.org/tcds/4A25): The Boeing Company; names 6 of 27 models: DC-8-72F, DC-8-73, DC-8-71, DC-8-72, DC-8-71F, DC-8-73F - [TCDS A3WE](https://openairdocs.org/tcds/A3WE): The Boeing Company; names 6 of 6 models: 727-100 Series, 727 Series, 727-200 Series, 727-100C Series, 727-200F Series, 727C Series - [TCDS 4A21](https://openairdocs.org/tcds/4A21): The Boeing Company; names 4 of 4 models: 707-100B Short Body, 707-200, 707-100 Long Body, 707-100B Long Body - [TCDS 4A26](https://openairdocs.org/tcds/4A26): The Boeing Company; names 4 of 4 models: 707-300B Series, 707-400 Series, 707-300 Series, 707-300C Series - [TCDS A5EU](https://openairdocs.org/tcds/A5EU): Airbus SAS; names 2 of 2 models: BAC 1-11 200 Series, BAC 1-11 400 Series ## 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: 984 (984 by airframe model, 0 by engine model) - Makers: Boeing 866, Mcdonnell Douglas 107, Douglas 11 Models with the most aircraft: - [Boeing 737-823](https://openairdocs.org/model/boeing-737-823): 278 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) - [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) - [Boeing 737-724](https://openairdocs.org/model/boeing-737-724): 36 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) - [Boeing 737-790](https://openairdocs.org/model/boeing-737-790): 14 aircraft (airframe model) - [Mcdonnell Douglas MD-88](https://openairdocs.org/model/mcdonnell-douglas-md-88): 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 727-223](https://openairdocs.org/model/boeing-727-223): 9 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) - [Boeing 737-500](https://openairdocs.org/model/boeing-737-500): 6 aircraft (airframe model) - [Boeing 737-436](https://openairdocs.org/model/boeing-737-436): 6 aircraft (airframe model) - [Boeing 737-700](https://openairdocs.org/model/boeing-737-700): 5 aircraft (airframe model) - [Boeing 727-227](https://openairdocs.org/model/boeing-727-227): 4 aircraft (airframe model) All 78 models: https://openairdocs.org/ad/97-04-04/models.md Every aircraft: https://openairdocs.org/ad/97-04-04/aircraft.md ## Related documents - [Proposed rule 96-ANE-15](https://openairdocs.org/proposed/96-ANE-15): Notice of proposed rulemaking (NPRM), published Aug 12, 1996 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.