AD 97-07-05

This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc. (formerly Textron Lycoming) T5311, T5313, T5317, and T53 series military engines approved for installation on aircraft certified in accordance with Section 21.25 of the Federal Aviation Regulations (FAR), that requires removal and replacement of the N2 spur gear nut retainer (lock cup). This amendment is prompted by reports of N2 spur gear nut retainer (lock cup) separation. The actions specified by this AD are intended to prevent N2 accessory drive assembly disengagement due to N2 spur gear nut retainer (lock cup) separation, which could result in an uncommanded engine acceleration.

Final rule.

97-07-05 AlliedSignal Inc.: Amendment 39-9979. Docket 96-ANE-25.
Applicability: AlliedSignal Inc. (formerly Textron Lycoming) T5311, T5313, T5317, and T53 (military) series turboshaft engines, installed on but not limited to Bell Helicopter Textron 209, 205, and 204 series, and Kaman K-1200 series aircraft, and the following military aircraft: Bell Helicopter Textron AH-1 and UH-1, and Grumman OV-1 (turboprop installation), certified in accordance with Section 21.25 or 21.27 of the Federal Aviation Regulations (FAR).
Note 1: 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 request approval for an alternative method of compliance in accordance with paragraph (b) 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 N2 accessory drive assembly disengagement due to N2 spur gear nut retainer (lock cup) separation, which could result in an uncommanded engine acceleration, accomplish the following:
(a) Within 300 hours time in service, or 2 years after the effective date of this AD, whichever occurs first, remove from service N2 spur gear nut retainers (lock cups), Part Number (P/N) 1-070-066-01, and replace with N2 spur gear nut retainers P/Ns 1-070-066-02 or 1-070-066- 03, in accordance with the following applicable AlliedSignal Aerospace Service Bulletins (SBs):
(1) For retainers installed on T5311 and T53-L-11 (military) series engines, in accordance with SB No. T5311/T53-L-11-0080, dated May 28, 1996.
(2) For retainers installed on T5313B and T5317 series engines, in accordance with SB No. T5313B/T5317-0081, Revision 1, dated May 28, 1996.
(3) For retainers installed on T53-L-13B/SSA/SSB (military) series engines, in accordance with SB No. T53-L-13B-0082, Revision 1, dated October 25, 1996.
(4) For retainers installed on T53-L-13B/SSD (military) series engines, in accordance with SB No. T53-L-13B/D-0083, dated May 28, 1996.
(5) For retainers installed on T53-L-703 (military) series engines, in accordance with SB No. T53-L-703-0084, Revision 1, dated October 25, 1996.
(b) 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 andthen send it to the Manager, Los Angeles Aircraft Certification Office.
Note 2: 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.
(c) 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.
(d) The actions required by this AD shall be done in accordance with the following AlliedSignal Engines SBs:

Document No
Pages
Revision
Date
T5311/T53-L-11-0080
1-4
Original
May 28, 1996
Total Pages: 4.

T5313B/T5317-0081
1-4
1
May 28, 1996
Total Pages: 4.

T53-L-13B-0082
1-4
1
October 25, 1996
Total Pages: 4.

T53-L-13B/D-0083
1-4
Original
May 28, 1996
Total Pages: 4.

T53-L-703-008
1-4
1
October 25,1996
Total Pages: 4.

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.
(e) This amendment becomes effective on June 24, 1997.

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 Textron Lycoming) T5311, T5313, T5317, and T53 series military engines approved for installation on aircraft certified in accordance with Section 21.25 of the Federal Aviation Regulations (FAR) was published in the Federal Register on November 13, 1996 (61 FR 58148). That action proposed to require removal and replacement of the N2 spur gear nut retainer (lock cup) with a more durable machined lock cup.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comment received.
The commenter (the manufacturer) states that the total time for access and replacement of the affected part should be changed from 3 hours to 16 hours to reflect access, removal, replacement, and closing. The FAA concurs andhas revised the economic analysis of this final rule accordingly.
Since issuance of the NPRM, the manufacturer has issued Revision 1, dated October 25, 1996, of AlliedSignal Engines Service Bulletin (SB) No. T53-L-13B-0082, and SB No. T53-L-703- 0084. This final rule AD references these later revisions.
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 not increase the scope of the AD.
There are approximately 450 (excluding military) engines of the affected design in the worldwide fleet. The FAA estimates that 125 (excluding military) engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 16 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 $75 per engine. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $129,375.
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: