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Proposed Rule

Airworthiness Directives; Honeywell International, Inc., (formerly AlliedSignal, Inc., Textron Lycoming, Avco Lycoming, and Lycoming) Former Military T53 Series Turboshaft Engines

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Honeywell International, Inc., (formerly AlliedSignal, Inc., Textron Lycoming, Avco Lycoming, and Lycoming) former military T53 series turboshaft engines (herein referred to as Lycoming) having certain part numbers of centrifugal compressor impellers installed. This proposal would require conducting a revised operating cycle count (prorate) and initial and repetitive inspections for cracks of those compressor impellers. This proposal is prompted by a report of a military surplus helicopter that experienced low-cycle fatigue failure of the centrifugal compressor impeller, resulting in an uncontained engine failure. The actions specified by the proposed AD are intended to prevent centrifugal compressor impeller failure, which can result in an uncontained engine failure, in-flight engine shutdown, or damage to the helicopter.

DATES:

Comments must be received by October 15, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-50-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: 9-ane-adcomment@faa.gov”. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Honeywell International, Inc., 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. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

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FOR FURTHER INFORMATION CONTACT:

Robert Baitoo, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone: (562) 627-5245, fax: (562) 627-5210.

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SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NE-50-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-50-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The FAA has become aware of a Lycoming former military T53 series turboshaft engine, installed on a Bell Helicopter Textron manufactured UH-1L military surplus helicopter, that experienced low-cycle fatigue failure of the centrifugal compressor impeller, resulting in an uncontained engine failure. In May 1995, the FAA published AD 95-10-04, dated May 25, 1995, to revise operating cycle counts (prorate) and require initial and repetitive inspections for cracks, for centrifugal compressor impellers, part numbers (P/N's) 1-100-78-07 and 1-100-078-08, installed on Lycoming former military T5313B and T5317 series turboshaft engines. Because centrifugal compressor impellers P/N's 1-100-78-07 and 1-100-078-08 are also installed on Lycoming former military T53 series engines, this proposal would require revising operating cycle counts (prorate) and require initial and repetitive inspections for cracks for centrifugal compressor impellers P/N's 1-100-078-07 and 1-100-078-08, installed on Lycoming former military T53 series turboshaft engines. This proposal is prompted by a report of a military surplus helicopter that experienced low-cycle fatigue failure of the centrifugal compressor impeller, resulting in an uncontained engine failure. These impellers, if not inspected for cracks using a revised cycle count could experience low-cycle fatigue failure, resulting in an uncontained engine failure, in-flight shutdown, or damage to the helicopter.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of Honeywell International, Inc. Service Bulletins (SB's) T53-L-13B-0020, Revision 2, dated April 25, 2001; T53-L-13B/D-0020, Revision 1, dated April 25, 2001; Start Printed Page 42971and T53-L-703-0020, Revision 1, dated April 25, 2001; that describe procedures for conducting a revised centrifugal compressor impeller operating cycle count (prorate) of impellers P/N's 1-100-078-07 and 1-100-078-08. The FAA has also reviewed and approved the technical contents of AlliedSignal, Inc. SB's T53-L-13B-0108, Revision 1, dated November 22, 1999; T53-L-13B/D-0108, Revision 1, dated November 22, 1999; and T53-L-703-0108, Revision 1, dated November 22, 1999; that describe procedures for special visual and fluorescent-penetrant inspections of centrifugal compressor impellers P/N's 1-100-078-07 and 1-100-078-08.

Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, the proposed AD would require initial and repetitive inspections of centrifugal compressor impellers, using a revised cycle count. The actions would be required to be done in accordance with the service bulletins described previously.

Economic Impact

The FAA estimates that there are approximately 300 Lycoming former military T53 series turboshaft engines installed on helicopters of U.S. registry, that would be affected by this proposed AD. The FAA also estimates that it would take approximately 8 work hours per engine to accomplish an initial or repetitive inspection of the centrifugal compressor impeller, and that the average labor rate is $60 per work hour. No additional work hour cost would be incurred if the centrifugal compressor impeller is replaced during normal engine disassembly. Based on these figures, the total labor cost impact of the proposed AD on U.S. operators for an inspection is estimated to be $144,000. The FAA estimates that operators will perform two inspections annually, and that the total annual labor cost for inspections is estimated to be $288,000. The cost of a replacement centrifugal compressor impeller is estimated to be $22,037. Assuming a loss of 50% of the life of each disk by the prorate, the total annual cost of the proposed AD on U.S. operators is estimated to be $3,593,550.

Regulatory Impact

This proposal does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposal.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Honeywell International, Inc. Docket 2000-NE-50-AD.

Applicability

This airworthiness directive (AD) is applicable to Honeywell International, Inc., (formerly AlliedSignal, Inc., Textron Lycoming, Avco Lycoming, and Lycoming) (herein referred to as Lycoming) former military T53-L-13B series, T53-L-13B/D series, and T53-L-703 series turboshaft engines with centrifugal compressor impellers part numbers (P/N's) 1-100-078-07 or 1-100-078-08 installed. These Lycoming engines are installed on, but not limited to, Bell Helicopter Textron manufactured AH-1, UH-1, and SW-204/205 (UH-1) series surplus military helicopters that have been certified in accordance with §§ 21.25 or 21.27 of the Federal Aviation regulations (14 CFR 21.25 or 21.27).

Note 1:

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 request approval for an alternative method of compliance in accordance with paragraph (e) 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

Compliance with this AD is required as indicated, unless accomplished previously.

To prevent centrifugal compressor impeller failure, which can result in an uncontained engine failure, in-flight engine shutdown, or damage to the helicopter, accomplish the following:

Centrifugal Compressor Impeller Revised Operating Cycle Count

(a) Within 25 operating cycles or 7 calendar days, whichever occurs first, after the effective date of this AD, do a revised centrifugal compressor impeller operating cycle count (prorate) in accordance with the accomplishment instructions of Honeywell International, Inc. Service Bulletin (SB) No. T53-L-13B-0020, Revision 2, dated April 25, 2001 for T53-L-13B Lycoming engines, SB No. T53-L-13B/D-0020, Revision 1, dated April 25, 2001 for T53-L-13B/D Lycoming engines, and SB No. T53-L-703-0020, Revision 1, dated April 25, 2001 for T53-L-703 Lycoming engines.

(b) Following the revised operating cycle count required by paragraph (a) of this AD, remove from service installed centrifugal compressor impellers that exceed their life limit or whose life cannot be determined, within 50 hours time-in-service (TIS), or 25 operating cycles, whichever occurs first and replace with a serviceable part that does not exceed the life limit.

(c) Installation of uninstalled centrifugal compressor impellers that exceed their life limit, which is revised in accordance with paragraph (a) of this AD is prohibited.

Centrifugal Compressor Impeller Inspections

(d) Following the revised operating cycle count required by paragraph (a) of this AD, inspect centrifugal compressor impellers, part numbers (P/N's) 1-100-078-07 and 1-100-078-08, in accordance with the accomplishment instructions of AlliedSignal, Inc. SB No. T53-L-13B-0108, Revision 1, dated November 22, 1999 for T53-L-13B Lycoming engines, SB No. T53-L-13B/D-0108, Revision 1, dated November 22, 1999 for T53-L-13B/D Lycoming engines, or SB No. T53-L-703-0108, Revision 1, dated November 22, 1999 for T53-L-703 Lycoming engines, as follows:

(1) For centrifugal compressor impellers with equal to or greater than 4,600 cycles-in-service (CIS), initially inspect within 200 CIS after the effective date of this AD.

(2) For those centrifugal compressor impellers with less than 4,600 CIS, initially inspect no later than 4,800 CIS.

(3) Centrifugal compressor impellers found cracked must be removed from service prior Start Printed Page 42972to further flight and replaced with a serviceable part.

(4) If no cracks are detected, perform repetitive inspections of the centrifugal compressor impellers at intervals not to exceed 500 CIS since last inspection.

Alternative Methods of Compliance

(e) 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 (ACO). Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permits

(f) 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 airplane to a location where the requirements of this AD can be accomplished.

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Issued in Burlington, Massachusetts, on August 7, 2001.

Diane S. Romanosky,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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[FR Doc. 01-20591 Filed 8-15-01; 8:45 am]

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