AD 95-12330

[Federal Register Volume 60, Number 97 (Friday, May 19, 1995)] [Proposed Rules] [Pages 26846-26848] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 95-12330]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 60, No. 97 / Friday, May 19, 1995 / Proposed Rules

[[Page 26846]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-08]

Airworthiness Directives; AlliedSignal Engines (Formerly Textron Lycoming) Models LTS101-650B1, -750B1, -650C, and -750C Turboshaft Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to AlliedSignal Engines (formerly Textron Lycoming) Models LTS101-650B1, -750B1, -650C, and -750C turboshaft engines. This proposal would require installation of an improved power turbine (PT) rotor and electronic PT rotor overspeed controller as a terminating action to the currently required inspections of AD 88-14-01. This proposal is prompted by reports of additional bearing failures since publication of AD 88-14-01, including one additional uncontained PT disk failure. The actions specified by the proposed AD are intended to prevent PT overspeed and uncontained engine failure.

DATES: Comments must be received by July 18, 1995.

.ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-ANE-08, 12 New England Executive Park, Burlington, MA 01803-5299. 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 AlliedSignal Inc., 550 Main Street, Stratford, CT 06497. This information may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7148, fax (617) 238-7199.

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 notice 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 95-ANE-08.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-ANE-08, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On May 26, 1988, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 88-14-01, Amendment 39-5952 (53 FR 25317, July 6, 1988), to require initial and repetitive inspections of the engine lubrication and bearing systems on AlliedSignal Engines (formerly Textron Lycoming) LTS101 series turboshaft engines. That action was prompted by reports of four uncontained power turbine (PT) disk failures. Subsequent investigation revealed that the PT disk failures were caused by bearing failures resulting in PT shaft disengagement from the gear train drive, unloading the PT and causing rotor overspeed. Two other PT disk failures involved No. 4 bearing failure, followed by power pinion gear teeth failure, thereby unloading the PT and causing PT rotor overspeed. This condition, if not corrected, could result in PT overspeed and uncontained engine failure. Since the issuance of that AD, the FAA has received reports of additional bearing failures with resultant loss of PT rotor location, including one additional uncontained PT disk failure. In order to minimize the possibility of an uncontained engine failure, the manufacturer has developed an improved PT rotor with retention capability and an improved electronic PT rotor overspeed controller. These improvements are only available for AlliedSignal Engines Models LTS101-650B1, -750B1, -650C, and -750C turboshaft engines, installed on Bell Helicopter Textron 222 series and Messerschmitt-Bolkow-Blohm (MBB) BK117 series helicopters. Installation of these improved components constitutes terminating action to the inspections required by AD 88-14- 01 only to these certain engine models installed on these certain helicopters. On October 28, 1994, AlliedSignal Inc. purchased the turbine engine product line of Textron Lycoming. The FAA has reviewed and approved the technical contents of the following Textron Lycoming Service Bulletins (SB), that describe installing an improved PT rotor with retention capability and an electronic PT rotor overspeed controller:

[[Page 26847]] ---------------------------------------------------------------------------------------------------------------- Engine model PT rotor Electronic overspeed ---------------------------------------------------------------------------------------------------------------- LTS101-650B............... LTS101B-72-50-0122, Revision 4, dated LTS101B-73-10-0127, Revision 2, dated June 17, 1991. August 14, 1992. LTS101-750B1.............. LTS101B-72-50-0116, Revision 6, dated LTS101B-73-10-0127, Revision 2 dated August 14, 1992. August 14, 1992. LTS101-650C and -750 LTS101C-72-50-0119, Revision 2, dated LTS101C-73-10-0129, Revision 3, dated Series. June 17, 1991. August 14, 1992. ----------------------------------------------------------------------------------------------------------------

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require installation of an improved PT rotor with retention capability and an electronic PT rotor overspeed controller at the next shop visit when the PT rotor is removed after the effective date of this AD, but prior to December 31, 1997, as a terminating action to the currently required inspections of AD 88-14-01. The FAA has determined, based on the availability of parts, that by that date affected engines would have at least one scheduled shop visit to install the improved components. In addition, by that date operators would have at least one scheduled opportunity to install components of the electronic overspeed controller in affected aircraft. The actions would be required to be accomplished in accordance with the service bulletins described previously. There are approximately 950 engines of the affected design in the worldwide fleet. The FAA estimates that 95 engines installed on aircraft of U.S. registry would be affected by the requirement to install the PT rotor with improved retention, that it would take approximately 10 work hours per engine to accomplish the proposed action, and that the average labor rate is $60 per work hour. Required parts cost for the PT rotor installation would be $44,400 per engine. Based on these figures, the cost impact of installing the PT rotor with improved retention is estimated to be $4,275,000. In addition, the FAA estimates that 576 engines installed on aircraft of U.S. registry would be affected by the requirement to install the electronic PT rotor overspeed controller, that it would take approximately 3 work hours per engine to accomplish the proposed action, and that the average labor rate is $60 per work hour. Required parts cost for the electronic PT rotor overspeed controller installation would be $5,825. Based on these figures, the cost impact of installing the electronic PT rotor overspeed controller would be $3,458,880. Therefore, the total cost impact of all the actions of the proposed AD on U.S. operators is estimated to be $7,733,880. The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a ``major rule'' under Executive Order 12291; (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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

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:

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.

Sec. 39.13 [Amended]

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

AlliedSignal Engines: Docket No. 95-ANE-08.

Applicability: AlliedSignal Engines (formerly Textron Lycoming) Model LTS101-650B1, -750B1, -650C, and -750C turboshaft engines installed on Bell Helicopter Textron 222 series and Messerschmitt- Bolkow-Blohm (MBB) BK117 series helicopters.

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 (d) 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 a request 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 power turbine (PT) overspeed and uncontained engine failure, accomplish the following: (a) Install the improved PT rotor with retention capability at the next shop visit when the PT rotor is removed after the effective date of this AD, but prior to December 31, 1997, in accordance with the following Textron Lycoming Service Bulletins (SB):

---------------------------------------------------------------------------------------------------------------- Engine model SB No. Rev. Date ---------------------------------------------------------------------------------------------------------------- LTS101-650B1.................................. LTS101B-72-50-0122 4 June 17, 1991. LTS101-750B1.................................. LTS101B-72-50-0116 6 August 14, 1992. LTS101-650C and -750C Series.................. LTS101C-72-50-0119 2 June 17, 1991. ----------------------------------------------------------------------------------------------------------------

(b) Install the improved electronic PT rotor overspeed controller concurrently with the PT rotor installation required by paragraph (a) of this AD in accordance with the following Textron Lycoming SB:

[[Page 26848]] ---------------------------------------------------------------------------------------------------------------- Engine model SB No. Rev. Date ---------------------------------------------------------------------------------------------------------------- LTS101-650B1.................................. LTS101-73-10-0127 2 August 14, 1992. LTS101-750B1.................................. LTS101-73-10-0127 2 August 14, 1992. LTS101-650C and -750C Series.................. LTS101-73-10-0129 3 August 14, 1992. ----------------------------------------------------------------------------------------------------------------

(c) Installation of the improved PT rotor with retention capability and the improved electronic PT rotor overspeed controller in accordance with paragraphs (a) and (b) of this AD constitutes terminating action to the inspection requirements of AD 88-14-01.

(d) 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 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.

(e) 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.

Issued in Burlington, Massachusetts, on May 15, 1995.

James C. Jones,

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

[FR Doc. 95-12330 Filed 5-18-95; 8:45 am]

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