[Federal Register Volume 61, Number 59 (Tuesday, March 26, 1996)]
[Proposed Rules]
[Pages 13113-13115]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7245]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-ANE-68]
Airworthiness Directives; AlliedSignal, Inc. TSCP700-4B, -4E, and
-5 Auxiliary Power Units
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, Inc. (formerly
Garrett) Models TSCP700-4B, -4E, and -5 auxiliary power units (APU's).
This proposal would require removal from service of certain high
pressure turbine (HPT) disks identified by serial number, and
replacement with serviceable parts. This proposal is prompted by the
discovery of a material defect in certain HPT disk forgings that may
result in HPT disk rupture prior to reaching the disk cyclic life
limit. The actions specified by the proposed AD are intended to prevent
an HPT disk rupture.
DATES: Comments must be received by May 28, 1996.
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-68, 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, P.O. Box 52181, Phoenix, AZ 85072-
2181; telephone (800) 338-3378, fax (602) 231-4402. 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: Robert Baitoo, Aerospace Engineer, Los
Angeles Aircraft Certification Office, FAA, Transport Airplane
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone
(310) 627-5245; fax (310) 627-5210.
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
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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-68.'' 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-68, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
The Federal Aviation Administration (FAA) received a report from
the manufacturer that a material defect exists in certain forgings of
high pressure turbine (HPT) disks installed on AlliedSignal, Inc.
(formerly Garrett) Models TSCP700-4B, -4E, and -5 auxiliary power units
(APU's). Analysis indicates that HPT disks forged from this material
may rupture prior to reaching the disk cyclic life limit of 30,000
cycles since new (CSN). This condition, if not corrected, could result
in an HPT disk rupture.
The FAA has reviewed and approved the technical contents of
AlliedSignal Aerospace Service Bulletin (SB) No. TSCP700-49-A7168,
dated November 7, 1995, that identifies by serial number HPT disks that
may have been forged with a material defect.
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 certain HPT disks
identified by serial number, and replacement with serviceable parts,
prior to accumulating 7,500 CSN, or 3 years after the effective date of
this AD, whichever occurs first. The FAA determined this calendar end-
date based upon the effect of the material defect on the HPT disks'
cyclic life. In addition, the FAA considered the rate of cyclic
accumulation on disks in service. The actions would be required to be
accomplished in accordance with the SB described previously.
There are approximately 31 APU's of the affected design in the
worldwide fleet. The FAA estimates that 20 APU's installed on aircraft
of U.S. registry would be affected by this proposed AD, and that no
additional work hours would be required if the disk is replaced during
overhaul. The manufacturer has advised the FAA that they will supply
required parts at no charge to the operator. The FAA has therefore
determined that this AD would impose no additional cost on U.S.
operators.
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
AlliedSignal, Inc.: Docket No. 95-ANE-68.
Applicability: AlliedSignal, Inc. (formerly Garrett) Models
TSCP700-4B, -4E, and -5 auxiliary power units (APU's), with high
pressure turbine (HPT) disks identified by serial number in
AlliedSignal Aerospace Service Bulletin (SB) No. TSCP700-49-A7168,
dated November 7, 1995. These APU's are installed on, but not
limited to, McDonnell Douglas DC-10, KC-10 (military), and MD-11
series, and Airbus A300 series aircraft.
Note: This airworthiness directive (AD) applies to each APU
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 APU's 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
Federal Aviation Administration (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 APU from the
applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent an HPT disk rupture, accomplish the following:
(a) Prior to accumulating 7,500 cycles since new (CSN), or 3
years after the effective date of this AD, whichever occurs first,
remove from service affected HPT disks and replace with a
serviceable part.
(b) The definition of a disk cycle may be found in the
applicable AlliedSignal, Inc. APU Component Maintenance Manual.
(c) Auxiliary Power Unit maintenance records may be used to
determine if the HPT disk installed in the APU has a serial number
listed in AlliedSignal Aerospace SB No. TSCP700-49-A7168, dated
November 7, 1995.
(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, Los Angeles Aircraft 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, Los Angeles Aircraft Certification Office.
[[Page 13115]]
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Los Angeles Aircraft 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 March 12, 1996.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 96-7245 Filed 3-25-96; 8:45 am]
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