AD 96-04-02

This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc. (formerly Textron Lycoming) ALF502L series turbofan engines, that establishes reduced retirement life limits for stage 1 and stage 3-7 compressors disks, and stage 2 turbine disks, and provides a drawdown schedule for disks already beyond the reduced retirement life limits. This amendment is prompted by new life analyses of these components. The actions specified by this AD are intended to prevent disk failure, which could result in an inflight engine shutdown and extensive engine damage.

Final rule.

96-04-02 AlliedSignal Inc.: Amendment 39-9513. Docket 94-ANE-56.
Applicability: AlliedSignal Inc. (formerly Textron Lycoming) ALF502L, L-2, L-2A, L-2C, and L-3 turbofan engines installed on but not limited to Canadair Challenger CL600 series aircraft. 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 theeffect 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 disk failure, which could result in an inflight engine shutdown and extensive engine damage, accomplish the following:
(a) Remove from service stage 1 and stage 3-7 compressor disks, and stage 2 turbine disks, in accordance with the drawdown schedule and procedures described in AlliedSignal Engines Service Bulletin (SB) No. ALF502L 72-281, dated November 30, 1994.
(b) This AD establishes new, reduced retirement life limits for stage 1 and stage 3-7 compressor disks, and stage 2 turbine disks, in accordance with AlliedSignal Engines SB No. ALF 502 72-0004, Revision 12, dated November 30, 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, 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.
(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 SB's:

Document No
Pages
Revision
Date
ALF502L 72-281
1-4
Original
November 30, 1994
Total pages: 4.

ALF 502 72-0004
1-23
12
November 30, 1994
Total pages: 23.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 Engines, 111 South 34th Street, Phoenix, AZ 85072; telephone (602) 365-2493, fax (602) 365-2210. 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 April 29, 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 Textron Lycoming) ALF502L series turbofan engines was published in the Federal Register on February 28, 1995 (60 FR 10811). That action proposed to establish reduced retirement life limits for stage 1 and stage 3-7 compressors disks, and stage 2 turbine disks, and provide a drawdown schedule for disks already beyond the reduced retirement life limits. These actions must be performed in accordance with AlliedSignal Engines Service Bulletin (SB) No. ALF 502 72-0004, Revision 12, dated November 30, 1994, that describes reduced retirement lives for affected components; and AlliedSignal Engines SB No. ALF502L 72-281, dated November 30, 1994, that describes a drawdown schedule for disks already beyond the reduced retirement life limits.
Interested persons have been afforded an opportunityto 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 184 engines of the affected design in the worldwide fleet. The FAA estimates that 50 engines installed on aircraft of U.S. registry will be affected by this AD, and that the prorated reduced service life cost based on the cost of a new disk is approximately $16,400 per engine. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $820,000.
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 Administrationamends 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: