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Proposed Rule

Airworthiness Directives; Honeywell International Inc. TPE331 Series Turboprop and TSE331-3U Series Turboshaft Engines

Document Details

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., Garrett Engine Division, Garrett Turbine Engine Company, and AiResearch Manufacturing Company of Arizona) TPE331 series turboprop and model TSE331-3U series turboshaft engines. This proposal would require replacing second stage turbine stator assemblies, part numbers (P/N's) 894528-1, -2, -3, -5, -6, -10, and -11, with serviceable turbine stator assemblies. This proposal is prompted by reports of six uncontained separations of the second stage turbine wheels. The actions specified by the proposed AD are intended to reduce fatigue damage of the second stage turbine stator inner seal support, rotating knife seal, and the second and third stage turbine wheels which may result in an uncontained rotor failure and damage to the aircraft.

DATES:

Comments must be received by April 22, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-53-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. 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.

The service information regarding the replacement and inspection of parts may be obtained from Honeywell Engines, Systems, and Services, Technical Data Distribution, M/S 2101-201, P.O. Box 52170, Phoenix, AZ 85072-2170; telephone: (602) 365-2493 (General Aviation), (602) 365-5535 (Commercial); fax: (602) 365-5577 (General Aviation and Commercial). 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:

Joseph Costa, Aerospace Engineer, Federal Aviation Administration, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd., Lakewood, CA 90712-4137; Telephone (562) 627-5246, 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NE-53-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. 99-NE-53-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

There have been six reported uncontained separations of second stage turbine wheels associated with obstructed internal cooling holes or passages in the vanes of the second stage turbine stator. The FAA has determined that obstructed cooling holes in the second stage turbine stator will increase turbine cavity temperatures. These elevated temperatures reduce the fatigue endurance capability of the turbine stator components and could cause the seal assembly to separate from the stator housing, or the rotating knife edge seal to separate from the turbine rotor. The stator seal support, stator seal assembly, or the rotating knife edge seal may then contact and rub into the turbine rotor, potentially resulting in an uncontained turbine rotor separation. Elevated cavity temperatures may also cause a reduction in the fatigue life of the turbine rotor and may result in an uncontained turbine rotor separation. In addition, the FAA has approved an air flow inspection and re-identification procedure for the second stage stator assemblies, P/N 894528-10 and -11. The FAA has not approved an air flow inspection of the older configurations of second stage stator assemblies, P/Ns 894528-1, -2, -3, -5, and -6, due to the difficulty to maintain the dimensional integrity of the stator assembly's internal cooling passages after the final braze operation of the stator's inner seal support or after welding of the stator's vanes. The FAA has approved repair procedures for converting the older configuration of second stage turbine Start Printed Page 7319stator assembly's inner seal support to a serviceable configuration. This condition, if not corrected, could result in increased fatigue damage of the second stage turbine stator inner seal support, rotating knife seal, and the second and third stage turbine wheels which may result in an uncontained rotor failure and damage to the aircraft.

FAA's Determination of an Unsafe Condition and Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other Honeywell International Inc. TPE331 series turboprop and TSE331-3U turboshaft engines of the same type design, the proposed AD would require replacing the existing second stage turbine stator assemblies, P/N's 894528-1, -2, -3, -5, -6, -10, and -11, with serviceable assemblies.

Economic Effect

There are approximately 4,700 engines of the affected design in the worldwide fleet. The FAA estimates that 2,350 engines installed on aircraft of U.S. registry would be affected by this proposed AD, that it would take approximately 4.0 work hours per engine to do the proposed actions, and that the average labor rate is $60 per work hour. Required replacement parts would cost approximately $8,000 per engine. Based on these figures, the total cost of the proposed AD on U.S. operators is estimated to be $14,958,000.

This proposed rule 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 proposed rule.

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 No. 99-NE-53-AD.

Applicability: This airworthiness directive (AD) is applicable to Honeywell International Inc. (formerly AlliedSignal Inc., Garrett Engine Division, Garrett Turbine Engine Company, and AiResearch Manufacturing Company of Arizona) Model TPE331-1, -2, -2UA, -3U, -3UW, -5, -5A, -5AB, -5B, -6, and -6A series turboprop and TSE331-3U Model turboshaft engines with second stage turbine stator assemblies, part numbers (P/N's) 894528-1, -2, -3, -5, -6, -10, and -11. These engines are installed on, but not limited to Ayres S-2R series; Beech 18 and 45 series and model JRB-6, 3N, 3NM, 3TM, and B100 airplanes; Construcciones Aeronauticas, S.A. (CASA) C-212; De Havilland DH104 series 7AXC (Dove); Dornier 228 series; Fairchild SA226 series (Swearingen Merlin and Metro series); Grumman American G-164 series; Mitsubishi MU-2 and MU-2B series; Pilatus PC-6 series (Fairchild Porter and Peacemaker); Prop-Jets, Inc. Model 400; Rockwell Commander S2-R; Schweizer G-164 series; Shorts Brothers and Harland, Ltd. SC7 (Skyvan); and Twin Commander 680 and 690 series (Jetprop Commander) airplanes; and Sikorsky S-55 series (Helitec Corp. S55T) helicopters.

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 (c) 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 already done.

To reduce fatigue damage of the second stage turbine stator inner seal support, rotating knife seal, and the second and third stage turbine wheels which may result in an uncontained rotor failure and damage to the aircraft, do the following:

(a) Replace second stage turbine stator assemblies, P/N's 894528-1, -2, -3, -5, -6, -10, and -11, with a new or reworked second stage turbine stator assembly at the next removal of the second stage turbine stator assembly from the engine or at the next turbine section inspection, but do not exceed 3,100 engine operating hours since last turbine section inspection. Information for replacing second stage turbine stator assemblies is available in Honeywell International Inc. Alert Service Bulletin (ASB) TPE331-A72-2082 dated May 16, 2001. Information for reworking second stage turbine stator assemblies is available in Honeywell International Inc. SB TPE331-72-2085RWK dated May 16, 2001.

(b) After the effective date of this AD, do not install any second stage turbine stator assembly P/N's 894528-1, -2, -3, -5, -6, -10, and -11.

Alternative Methods of Compliance

(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 (LAACO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, LAACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the LAACO.

Special Flight Permits

(d) Special flight permits may be issued in accordance §§ 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 done.

Start Signature

Issued in Burlington, Massachusetts, on February 12, 2002.

Francis A. Favara,

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

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[FR Doc. 02-3877 Filed 2-15-02; 8:45 am]

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