[Federal Register Volume 60, Number 83 (Monday, May 1, 1995)]
[Proposed Rules]
[Pages 21053-21054]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-10594]
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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.
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Federal Register / Vol. 60, No. 83 / Monday, May 1, 1995 / Proposed
Rules
[[Page 21053]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-ANE-21]
Airworthiness Directives; AlliedSignal Engines LTS101 Series
Turboshaft Engines Installed on Eurocopter France Model AS-350D and SA-
366G1 Helicopters
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), applicable to AlliedSignal Engines (formerly Textron
Lycoming) LTS101 series turboshaft engines installed on Eurocopter
France (formerly Aerospatiale) Model AS-350D and SA-366G1 helicopters.
This proposal would require incorporation of design modifications to
the power turbine (PT) rotor. This proposal is prompted by reports of
PT disk failures after No. 3 bearing failures. The actions specified by
the proposed AD are intended to prevent an uncontained engine failure
due to a PT disk failure.
DATES: Comments must be received by June 30, 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-21, 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 Engines, 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-21.'' 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-21, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
The Federal Aviation Administration (FAA) has received reports of
three uncontained power turbine (PT) disk failures on AlliedSignal
Engines (formerly Textron Lycoming) LTS101 series turboshaft engines.
These PT disk failures were caused by No. 3 bearing failures, resulting
in loss of rotor axial location, aft movement of the PT rotor, and PT
shaft disengagement from the gear train drive, subsequently unloading
the PT and causing rotor overspeed. The disengagement further rendered
the gear train drive overspeed control inoperative; therefore, the PT
overspeed progressed until disk failure. This condition, if not
corrected, could result in an uncontained engine failure due to a PT
disk failure.
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 Textron
Lycoming Service Bulletin (SB) No. LTS101A-72-50-0134, Revision 1,
dated June 17, 1991, and SB No. LTS101B-72-50-0128, Revision 1, dated
June 17, 1991, that describe procedures for incorporation of design
modifications to the PT to enhance rotor retention in the event of No.
3 bearing failure.
At the present time, this proposed airworthiness directive (AD)
would require only the PT rotor retention modifications for
AlliedSignal Engines Model LTS101-600A2, -600A3, and -750B2 engines.
AlliedSignal Engines and several airframe manufacturers have developed
electronic overspeed system (EOS) modifications for other models of the
AlliedSignal Engines LTS101 series turboshaft engines. These other
modifications address additional disk failures precipitated by No. 4
bearing failure, which in two cases led to power pinion gear failure
and PT shaft disengagement from the power train without loss of rotor
axial location, overspeed, and loss of PT overspeed protection. In
separate rulemaking, the FAA will require these EOS modifications for
these other models. Airworthiness directive 88-14-01, applicable to all
Textron Lycoming LTS101 engines, requires repetitive inspections and
monitoring of the lubrication system to prevent PT rotor disk failures
due to failure of either No. 3 or No. 4 bearings. Performing the PT
rotor and EOS modifications on these other models would constitute
terminating action for the inspections and monitoring required by AD
88-14- [[Page 21054]] 01. The FAA has requested that AlliedSignal
Engines and Eurocopter France develop EOS modifications for the
AlliedSignal Engines LTS101 models addressed in this proposed AD. When
these modifications are available, the FAA will require these
modifications in future rulemaking that would constitute terminating
action to the inspection and monitoring requirements of AD 88-14-01.
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 incorporation of a modified PT rotor
retention system at the next shop visit after the effective date of
this AD, but not later than April 30, 1996. The FAA has determined that
by that date affected engines would have at least one scheduled shop
visit to incorporate modifications. The actions would be required to be
accomplished in accordance with the service bulletins described
previously.
The FAA estimates that 20 engines installed on aircraft of U.S.
registry would be affected by this proposed AD, that it would take
approximately 10 work hours per engine to accomplish the proposed
actions, and that the average labor rate is $60 per work hour. Required
parts would cost approximately $44,400 engine. Based on these figures,
the total cost impact of the proposed AD on U.S. operators is estimated
to be $900,000.
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-21.
Applicability: AlliedSignal Engines (formerly Textron Lycoming)
Models LTS101-600A2 and -600A3 turboshaft engines installed on
Eurocopter France (formerly Aerospatiale) Model AS-350D helicopters;
and LTS101-750B2 turboshaft engines installed on Eurocopter France
Model SA-366G1 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 (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 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 an uncontained engine failure due to power turbine
(PT) disk failure, accomplish the following:
(a) Incorporate improved PT rotor retention system modifications
in accordance with Textron Lycoming Service Bulletin (SB) No.
LTS101A-72-50-0134, Revision 1, dated June 17, 1991, or SB No.
LTS101B-72-50-0128, Revision 1, dated June 17, 1991, as applicable,
at the next shop visit after the effective date of this
airworthiness directive (AD) when the PT rotor is removed, but not
later than April 30, 1996.
(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 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
Secs. 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 April 17, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-10594 Filed 4-28-95; 8:45 am]
BILLING CODE 4910-13-P
