AD 96-06-11

This amendment adopts a new airworthiness directive (AD), applicable to certain AlliedSignal Inc. (formerly Garrett Engine Division) TPE331 series turboprop engines, that establishes cyclic retirement lives for certain compressor components. This amendment is prompted by manufacturer's engine testing and analysis that indicate that if these compressor components continue in service without an established retirement life, accumulative cyclic effects may result in a fatigue failure. The actions specified by this AD are intended to prevent fatigue failure of engine compressor components and an inflight engine shutdown.

Final rule.

96-06-11 AlliedSignal Inc.: Amendment 39-9548. Docket 95-ANE-09.
Applicability: AlliedSignal Inc. (formerly Garrett Engine Division) Models TPE331-14A, -14B, -14F, and -15AW turboprop engines, installed on but not limited to the following aircraft: Piper Model PA-42-1000 and Grumman Model TS-2A (modified in accordance with Supplemental Type Certificate SA4837NM). NOTE: This airworthiness directive (AD) applies to each engine 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 engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (c) to request approval from the Federal Aviation Administration (FAA). This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any engine from the applicability of this AD.
Compliance: Required as indicated, unless accomplished previously.
To prevent fatigue failure of engine compressor components and an inflight engine shutdown, accomplish the following:
(a) For main shouldered shafts (tieshafts), Part Number (P/N) 3105102-1, initiate a life limited part log card and remove from service in accordance with the following schedule and the following AlliedSignal Inc. Alert Service Bulletins (ASB's):
(1) Determine cycles in service (CIS) for the main shouldered shafts (tieshafts) as follows:
(i) For main shouldered shafts (tieshafts) installed in TPE331-14A and -14B engines, in accordance with ASB No. TPE331-A72-7128, datedJune 10, 1994.
(ii) For main shouldered shafts (tieshafts) installed in TPE331-14F engines, in accordance with ASB No. TPE331-A72-7129, dated June 10, 1994.
(iii) For main shouldered shafts (tieshafts) installed in TPE331-15AW engines, in accordance with ASB No. TPE331-A72-7522, dated February 17, 1995.
(2) For main shouldered shafts (tieshafts) with greater than 5,600 CIS on the effective date of this airworthiness directive (AD), or if operating hours or cycles are unknown, remove from service within 400 CIS after the effective date of this AD.
(3) For main shouldered shafts (tieshafts) with 5,600 or less CIS on the effective date of this AD, remove from service prior to accumulating 6,000 CIS.
(b) For forward coupling shafts (stub shafts), P/N 3104281-2, initiate a life limited part log card, identify the P/N, serialize the forward coupling shaft (stub shaft), at the next major periodic inspection or complete disassembly of the compressor module after the effective date of this AD, whichever occurs first, in accordance with the following AlliedSignal Inc. Service Bulletins (SB's):
(1) For forward coupling shafts (stub shafts) installed in TPE331-14A and -14B engines, in accordance with SB No. TPE331-72-7130, dated June 17, 1994.
(2) For forward coupling shafts (stub shafts) installed in TPE331-14F engines, in accordance with SB No. TPE331-72-7131, dated June 17, 1994.
(3) For forward coupling shafts (stub shafts) installed in TPE331-15AW engines, in accordance with SB No. TPE331-72-7523, dated February 17, 1995.
(4) Remove from service forward coupling shafts (stub shafts) prior to accumulating 20,000 CIS. NOTE: For guidance on the destruction or marking of parts no longer serviceable for aviation use, see Advisory Circular 21-38, dated July 5, 1994.
(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: 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.
(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 AlliedSignal Engines service documents:

Document No
Pages
Revision
Date
ASB No. TPE331-A72-7128
1-4
Original
June 10, 1994
Total Pages: 4.

ASB No. TPE331-A72-7129
1-4
Original
June 10, 1994
Total Pages: 4.

ASB No. TPE331-A72-7522
1-2
Original
February 17, 1995
Total Pages: 2.

SB No. TPE331-72-7130
1-6

Original
June 17, 1994
Total Pages: 6.

SB No. TPE331-72-7131
1-6
Original
June 17, 1994
Total Pages: 6.

SB No. TPE331-72-7523
1-6
Original
February 17, 1995
Total pages: 6

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, Data Distribution, M/S 6403/2101-201, 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 May 28, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to AlliedSignal Inc. (formerly Garrett Engine Division) Models TPE331-14A, -14B, -14F, and -15AW turboprop engines was published in the Federal Register on June 19, 1995 (60 FR 31932). That action proposed to establish cyclic retirement lives for main shouldered shafts (tieshafts) and forward coupling shafts (stub shafts) in accordance with the following AlliedSignal Engines service documents: Alert Service Bulletins (ASB's): No. TPE331-A72-7128, dated June 10, 1994, No. TPE331-A72-7129, dated June 10, 1994, and No. TPE331-A72-7522, dated February 17, 1995, that describe main shouldered shaft (tieshaft) cyclic life limits; and Service Bulletins (SB's) No. TPE331-72-7130, dated June 17, 1994, No. TPE331-72-7131, dated June 17, 1994, and No. TPE331-72-7523, dated February 17, 1995, that describe forward coupling shaft (stub shaft) cyclic life limits.
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.
There are approximately 200 engines of the affected design in the worldwide fleet. The FAA estimates that 150 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 80 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $22,000 per engine for engines where tieshafts and stub shafts are not serviceable. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $4,020,000.
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 adding the following new airworthiness directive: