[Federal Register Volume 62, Number 35 (Friday, February 21, 1997)]
[Rules and Regulations]
[Pages 7932-7934]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4098]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-ANE-15; Amendment 39-9927; AD 97-04-04]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. GTCP85 Series 
Auxiliary Power Units

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to AlliedSignal Inc. (formerly Garrett Auxiliary Power 
Division) GTCP85 Series auxiliary power units (APUs), that currently 
requires removing the existing turbine wheel shroud and installing one 
constructed of Hastelloy ``S'' material, or installing a containment 
augmentation ring. This amendment deletes the option of installing a 
turbine shroud constructed of Hastelloy ``S'' material. This amendment 
is prompted by a report of insufficient APU containment capability with 
the Hastelloy ``S'' shroud alone installed. The actions specified by 
this AD are intended to prevent turbine shroud fragments from exiting 
the APU and puncturing the APU compartment, which could result in 
reduced fire extinguishing capability in the APU compartment.

DATES: Effective March 24, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 24, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from AlliedSignal Aerospace, Attn: Data Distribution, M/S 64-
3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 
365-2493, fax (602) 365-5577. This information may be examined at the 
Federal Aviation Administration (FAA), New England Region, Office of 
the Assistant Chief Counsel, 12 New England Executive Park, Burlington, 
MA 01803-5299; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-07-13, 
Amendment 39-8545 (58 FR 21917, April 26, 1993), which is applicable to 
AlliedSignal Inc. (formerly Garrett Auxiliary Power Division) GTCP85 
Series auxiliary power units (APUs), was published in the Federal 
Register on August 12, 1996 (61 FR 41751). That action proposed to 
require installing an improved containment augmentation ring, Part 
Number (P/N) 3616426-1, or P/N 3616426-3, which is a redesigned 
containment augmentation ring to allow installation on certain APUs 
that cannot accept the -1 containment augmentation ring. The 
containment augmentation rings, P/Ns 3616426-1 and 3616426-3, improve 
the containment capability of the APU relative to the earlier 
containment augmentation ring, P/N 3612249-1, by preventing turbine 
shroud fragments from passing around the containment augmentation ring. 
The installation must be accomplished within 24 months after the 
effective date of this AD, for flight operable APUs, and within 36 
months after the effective date of this AD, for APUs that are operable 
on the ground only. The actions would be required to be accomplished in 
accordance with AlliedSignal Aerospace Alert Service Bulletin (ASB) No.

[[Page 7933]]

GTCP85-49-A7189, Revision 2, dated October 8, 1996, AlliedSignal 
Aerospace ASB No. GTCP85-49-A7189, Revision 1, dated July 19, 1996, or 
AlliedSignal Aerospace ASB No. GTCP85-49-A7189, Original, dated March 
29, 1996; and AlliedSignal Aerospace ASB No. GTCP85-49-A6706, Revision 
2, dated November 28, 1994, AlliedSignal Aerospace ASB No. GTCP85-49-
A6706, Revision 1, dated November 12, 1993, or Garrett ASB No. GTCP85-
49-A6706, Original, dated December 7, 1992.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter states that the AD should apply only to APUs with 
one-piece cast turbine wheels made of MAR-M-247 material, as only these 
type turbine wheels have failed in the commenter's experience. The FAA 
concurs in part. The proposed rule as written applies to APUs with one-
piece cast turbine wheels with the listed P/Ns, which are made of MAR-
M-247 material, but also Inconel, which have failed as well.
    Two commenters state that the AD should add an additional method of 
compliance by replacing the one-piece cast turbine wheels with two-
piece wheels. The FAA does not concur. The proposed AD does not apply 
to APUs with two-piece turbine wheels.
    One commenter (the manufacturer) states that the economic analysis 
provides figures for the number of APUs in service domestically and 
worldwide that are too low. The FAA concurs and revised the economic 
analysis of this final rule accordingly.
    One commenter states that the proposed AD should be more clear in 
stating that compliance is acceptable with either ASB stated in 
paragraphs (a)(1) and (a)(2) and (b)(1) and (b)(2) of the compliance 
section. The FAA concurs and has put the ``or'' between the appropriate 
paragraphs in bold type to highlight its significance.
    Two commenters concur with the AD as proposed.
    Since publication of the proposed rule, AlliedSignal Aerospace has 
issued Revision 2 to ASB No. GTCP85-49-A7189, dated October 8, 1996, 
which is referenced in this final rule along with Revision 1, dated 
July 19, 1996, and Original, dated March 29, 1996. These revisions of 
that ASB are all approved methods of compliance for the appropriate 
paragraphs of this AD.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 4,100 APUs of the affected design in the 
worldwide fleet. The FAA estimates that 1,300 APUs installed on 
aircraft of U.S. registry will be affected by this AD, that it will 
take no additional work hours if the required actions are accomplished 
when the APU is already disassembled in the shop. Required parts will 
cost approximately $1,550 per APU. Based on these figures, the total 
cost impact of the AD on U.S. operators is estimated to be $2,015,000.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air Transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8545 (52 FR 
45163, November 25, 1987) and by adding a new airworthiness directive, 
Amendment 39-9927, to read as follows:

97-04-04  AlliedSignal Inc.: Amendment 39-9927. Docket 96-ANE-15. 
Supersedes AD 93-07-13, Amendment 39-8545.

    Applicability: AlliedSignal Inc. (formerly Garrett Auxiliary 
Power Division) GTCP85 series auxiliary power units (APUs), 
incorporating a one-piece cast turbine wheel, Part Numbers (P/Ns) 
968095-X, 3604604-X, 3606982-1, or 3842072-X (where ``X'' denotes 
any number). These APUs are installed on but not limited to the 
following aircraft: British Aerospace BAC 1-11 series; Boeing 707, 
727, and 737 series; Lockheed L382 series; and McDonnell Douglas DC-
8-70, DC-9, and MD-88 series aircraft.

    Note 1: 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 APUs 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: Required as indicated, unless accomplished 
previously.
    To prevent turbine shroud fragments from exiting the APU and 
puncturing the APU compartment, which could result in reduced fire 
extinguishing capability in the APU compartment, accomplish the 
following:
    (a) For flight operable APUs, within 24 months after the 
effective date of this AD, accomplish either of the following:
    (1) Install a containment augmentation ring, P/N 3616426-3, in 
accordance with AlliedSignal Aerospace Alert Service Bulletin (ASB) 
No. GTCP85-49-A7189, Revision 2, dated October 8, 1996, Revision 1, 
dated July 19, 1996, or Original, dated March 29, 1996; or
    (2) Install a containment augmentation ring, P/N 3616426-1, in 
accordance with AlliedSignal Aerospace ASB No.GTCP85-49-A6706, 
Revision 2, dated November 28, 1994, AlliedSignal Aerospace ASB No. 
GTCP85-49-A6706, Revision 1, dated November 12, 1993, or Garrett ASB 
No. GTCP85-49-A6706, Original, dated December 7, 1992.
    (b) For APUs that are operable on the ground only, within 36 
months after the effective date of this AD, accomplish either of the 
following:
    (1) Install a containment augmentation ring, P/N 3616426-3, in 
accordance with AlliedSignal Aerospace ASB No. GTCP85-

[[Page 7934]]

49-A7189, Revision 2, dated October 8, 1996, Revision 1, dated July 
19, 1996, or Original, dated March 29, 1996; or
    (2) Install a containment augmentation ring, P/N 3616426-1, in 
accordance with AlliedSignal Aerospace ASB No. GTCP85-49-A6706, 
Revision 2, dated November 28, 1994, AlliedSignal Aerospace ASB No. 
GTCP85-49-A6706, Revision 1, dated November 12, 1993, or Garrett ASB 
No. GTCP85-49-A6706, Original, dated December 7, 1992.
    (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. 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.

    Note 2: Information concerning the existence of approved 
alternative method of compliance with this AD, if any, may be 
obtained from the Los Angeles Aircraft Certification Office.

    (d) 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.
    (e) The actions required by this AD shall be done in accordance 
with the following ASBs:

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            Document No.                    Pages                  Revision                      Date           
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AlliedSignal Aerospace, GTCP85-49-   1-14...............  2.........................  Oct. 8, 1996.             
 A7189.                                                                                                         
    Total pages: 14.                                                                                            
AlliedSignal Aerospace, GTCP85-49-   1-12...............  1.........................  July 19, 1996.            
 A7189.                                                                                                         
    Total pages: 12.                                                                                            
AlliedSignal Aerospace, GTCP85-49-   1-10...............  Original..................  Mar. 29, 1996.            
 A7189.                                                                                                         
    Total pages: 10.                                                                                            
AlliedSignal Aerospace, GTCP85-49-   1..................  2.........................  Nov. 28, 1994.            
 A6706.                                                                                                         
                                     2, 3...............  1.........................  Nov. 12, 1993.            
                                     4..................  2.........................  Nov. 28, 1994.            
                                     5-8................  1.........................  Nov. 12, 1993.            
                                     9, 10..............  2.........................  Nov. 28, 1994.            
    Total pages: 10.                                                                                            
                                                                                                                
AlliedSignal Aerospace GTCP85-49-    1-10...............  1.........................  Nov. 12, 1993             
 A6706                                                                                                          
    Total pages: 10.                                                                                            
Garrett GTCP85-49-A6706............  1, 2...............  Original..................  Dec. 7, 1992              
                                     4-10...............  Original..................  Dec. 7, 1992.             
    Total pages: 9.                                                                                             
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from AlliedSignal Aerospace, Attn: 
Data Distribution, M/S 64-3/2101-201, P.O. Box 29003, Phoenix, AZ 
85038-9003; telephone (602) 365-2493, fax (602) 365-5577. Copies may 
be inspected at the FAA, New England Region, Office of the Assistant 
Chief Counsel, 12 New England Executive Park, Burlington, MA; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
Suite 700, Washington, DC.
    (f) This amendment becomes effective on March 24, 1997.

    Issued in Burlington, Massachusetts, on February 4, 1997.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 97-4098 Filed 2-20-97; 8:45 am]
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