[Federal Register Volume 60, Number 93 (Monday, May 15, 1995)]
[Proposed Rules]
[Pages 25869-25871]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-11903]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 93-ANE-64]
Airworthiness Directives; AlliedSignal Engines (Formerly Textron
Lycoming) LTS 101 Series Turboshaft and LTP 101 Series Turboprop
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) LTS 101 series turboshaft and LTP 101 series
turboprop engines. This proposal would require removal from service of
suspect disks for a one-time inspection of the disk tenon area of the
gas generator turbine disk. This proposal is prompted by a report of a
gas generator turbine disk tenon failure. The actions specified by the
proposed AD are intended to prevent total loss of engine power,
inflight engine shutdown, and possible damage to the aircraft.
DATES: Comments must be received by July 14, 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. 93-ANE-64, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location between 8 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 [[Page 25870]] Docket Number 93-ANE-64.'' 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. 93-ANE-64, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
The Federal Aviation Administration (FAA) has received a report of
a gas generator turbine disk tenon failure on an AlliedSignal Engines
(formerly Textron Lycoming) LTS 101 turboshaft engine. The FAA
investigation revealed that the disk had sharp-edged grooves in the
disk blade slots created in the broaching operations that occurred
during manufacturing. These grooves significantly reduce the cyclic
life of disk tenons. This condition, if not corrected, could result in
total loss of engine power, inflight engine shutdown, and possible
damage to the aircraft.
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. LT 101-72-50-0150, dated September
1, 1993, that describes procedures for removal from service of suspect
disks for a one-time inspection of the disk tenon area of the gas
generator turbine disk.
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 removal from service of suspect disks for a
one-time inspection of the disk tenon area of the gas generator turbine
disk. The actions would be required to be accomplished in accordance
with the service bulletin described previously.
The FAA estimates that 618 engines installed on aircraft of U.S.
registry would be affected by this proposed AD, that it would take
approximately 6.5 work hours per engine to accomplish the proposed
actions, and that the average labor rate is $60 per work hour.
AlliedSignal Engines has advised that they will supply disks or rotors
on an exchange basis at no cost to the operator. Based on these
figures, the total cost impact of the proposed AD on U.S. operators is
estimated to be $229,896.
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 ``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.
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. 93-ANE-64.
Applicability: AlliedSignal Engines (formerly Textron Lycoming)
LTS 101 series turboshaft and LTP 101 series turboprop engines
installed on but not limited to Aerospatiale AS 350 and SA366G, Bell
222, and Messerschmitt-Bolkow-Blohm (MBB) BK117 helicopters; and
Piaggio P166-DL3 and Airtractor AT302 airplanes.
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 total loss of engine power, inflight engine shutdown,
and possible damage to the aircraft, accomplish the following:
(a) Remove from service suspect disks and perform a one-time
inspection of the disk tenon area of the gas generator turbine disk,
and replace, if necessary, with a serviceable part, in accordance
with Textron Lycoming Service Bulletin (SB) No. LT 101-72-50-0150,
dated September 1, 1993, as follows:
(1) For disks with greater than 5,000 cycles since new (CSN) on
the effective date of this AD, remove within 235 cycles in service
(CIS).
(2) For disks with 4,501 to 5,000 CSN on the effective date of
this AD, remove within 285 CIS.
(3) For disks with 4,001 to 4,500 CSN on the effective date of
this AD, remove within 350 CIS.
(4) For disks with 3,501 to 4,000 CSN on the effective date of
this AD, remove within 450 CIS.
(5) For disks with 3,001 to 3,500 CSN on the effective date of
this AD, remove within 600 CIS.
(6) For disks with 2,501 to 3,000 CSN on the effective date of
this AD, remove within 800 CIS, or prior to accumulating 3,400 CSN,
whichever occurs later.
(7) For disks with 2,001 to 2,500 CSN on the effective date of
this AD, remove within 1,100 CIS, or prior to accumulating 3,400
CSN, whichever occurs later.
(8) For disks with less than 2,000 CSN on the effective date of
this AD, remove prior to accumulating 3,400 CSN.
(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 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.
(c) 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.
[[Page 25871]] Issued in Burlington, Massachusetts, on May 1,
1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-11903 Filed 5-12-95; 8:45 am]
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