AD 95-16-04

This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc. LTS101 series turboshaft and LTP101 series turboprop engines, that requires replacement of cast material axial compressor rotors with wrought material axial compressor rotors that have improved fatigue characteristics and material properties. This amendment is prompted by 36 reports of axial compressor blade failures on cast rotors. The actions specified by this AD are intended to prevent engine power loss and inflight engine shutdown.

Final rule.

95-16-04 AlliedSignal, Inc.: Amendment 39-9323. Docket 94-ANE-64.
Applicability: AlliedSignal, Inc. (formerly Textron Lycoming) LTS101 turboshaft and LTP101 turboprop engines installed on but not limited to Aerospatiale AS 350 and SA366G, Bell 222, and Messerschmitt-Bolkow-Blohm (MBB) BK117 helicopters; Piaggio P166-DL3 and Airtractor AT302 airplanes.
NOTE: This 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 (b) to request approval from the 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 arequest 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 engine power loss and inflight engine shutdown, accomplish the following:
(a) Remove from service Part Numbers (P/N) 4-101-006-20, -21, -24, -26, -35, -36, and -40 cast material axial compressor rotors, as follows:
(1) For axial compressor rotors P/N 4-101-006-35 with serial number suffix "E," remove in accordance with Textron Lycoming Service Bulletin (SB) No. LT 101-72-30-0088, Revision 5, dated September 25, 1992, within 50 hours time in service (TIS), or 60 days after the effective date of this AD, whichever occurs first.
(2) For axial compressor rotors P/N 4-101-006-35 with serial number suffix other than "E," and all other axial compressor rotors with P/N listed in paragraph (a) of this airworthiness directive (AD), remove in accordance with Textron Lycoming SB No. LT 101-72-30-0088, Revision 5, dated September 25, 1992, as follows:
(i) For axial compressor rotors that have accumulated 600 hours or less TIS since new, remove within 100 hours TIS, or 120 days after the effective date of this AD, whichever occurs first.
(ii) For axial compressor rotors that have accumulated more than 600 but less than or equal to 1,200 hours TIS since new, remove within 300 hours TIS, or 240 days after the effective date of this AD, whichever occurs first.
(iii) For axial compressor rotors that have accumulated more than 1,200 but less than or equal to 2,400 hours TIS since new, remove within 600 hours TIS, or 360 days after the effective date of this AD, whichever occurs first.
(iv) For axial compressor rotors that have accumulated more than 2,400 hours TIS since new, remove within 1,200 hours TIS, or 720 days afterthe effective date of this AD, whichever occurs first.
(3) Replace with a serviceable wrought material axial compressor rotor P/N 4-101- 006-28, -32, -39, or -41, as applicable, in accordance with Textron Lycoming SB No. LT 101-72-30- 0088, Revision 5, dated September 25, 1992.
(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, Engine 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, Engine Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine 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 SB:

Document No.
Pages
Revision
Date
Textron Lycoming SB No. LT 101-72- 30-0088

1-4

5

September 25, 1992
Total Pages: 5.

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, Inc., 550 Main Street, Stratford, CT 06497. 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 October 2, 1995.

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) LTS101 series turboshaft and LTP101 series turboprop engines was published in the Federal Register on January 4, 1995 (60 FR 393). That action proposed to require replacing cast material axial compressor rotors with wrought material axial compressor rotors that have improved fatigue characteristics and material properties, in accordance with Textron Lycoming Service Bulletin No. LT 101-72-30-0088, Revision 5, dated September 25, 1992.
On October 28, 1994, AlliedSignal Inc. purchased the turbine engine product line of Textron Lycoming, and this final rule has been revised to refer to the engine by its new name.
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 with the change described previously.
There are approximately 200 engines of the affected design in the worldwide fleet. The FAA estimates that 100 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 50 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 $6,500 per engine, on a prorated cost basis. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $955,000.
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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 39.13 - [AMENDED]
2. Section 39.13 is amended by adding the following new airworthiness directive: