[Federal Register Volume 62, Number 183 (Monday, September 22, 1997)]
[Rules and Regulations]
[Pages 49427-49429]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24910]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-03; Amendment 39-10138; AD 97-19-18]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. TSCP700-4B and -5 
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 AiResearch and Garrett) 
TSCP700-4B and -5 Series Auxiliary Power Units (APUs), that currently 
requires restretching the first stage low pressure compressor (LPC) tie 
rods, or replacing affected disks at or before 8,000 cycles since new 
(CSN). This amendment requires removing from service affected disks, 
replacing them with serviceable parts, and establishing a life limit of 
8,000 CSN for affected disks. This amendment is prompted by a report of 
a first stage LPC disk rim separation due to low cycle fatigue on an 
APU that had its tie rods restretched in accordance with the current 
AD. The actions specified by this AD are intended to prevent first 
stage LPC disk rim separation due to low cycle fatigue, which could 
result in an uncontained APU failure and damage to the aircraft.

DATES: Effective October 27, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 27, 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

[[Page 49428]]

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 
(562) 627-5245; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 88-24-07, 
Amendment 39-6062 (53 FR 46439, November 17, 1988), which is applicable 
to AlliedSignal Inc. (formerly AiResearch and Garrett) TSCP700-4B and -
5 series auxiliary power units (APUs), was published in the Federal 
Register on March 18, 1997 (62 FR 12774). That action proposed to 
eliminate the option of restretching the tie rods, and require removing 
from service affected disks in accordance with a schedule derived from 
calculations in AlliedSignal Inc. Service Bulletin (SB) No. TSCP700-49-
7266, dated June 16, 1996, replacing affected disks with serviceable 
parts, and establishing a life limit of 8,000 cycles since new (CSN) 
for affected disks.
    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 (the manufacturer) states that the AD should not 
imply that the tie rod restretch is ineffective, as the manufacturer 
believes that the tie rod restretch is beneficial in minimizing disk 
liberation. The FAA concurs that tie rod restretching is beneficial; 
however, the FAA has determined through analysis that the life limit of 
affected disks must be reduced to 8,000 CSN regardless of tie rod 
restretch in order to ensure safe operation.
    Three commenters concur with the rule as proposed.
    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.
    The FAA estimates that 100 APUs installed on aircraft of U.S. 
registry will be affected by this AD, no additional work hours per APU 
to accomplish the proposed actions if the actions are accomplished 
during APU overhaul, 8 work hours to accomplish the required actions if 
the actions are not accomplished during APU overhaul, and that the 
average labor rate is $60 per work hour. Based on these figures, and 
that the work would not be performed during overhaul, the total cost 
impact of the AD on U.S. operators is estimated to be $48,000.
    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 39-6062 (53 FR 
46439, November 17, 1988) and by adding a new airworthiness directive, 
Amendment 39-XXXX, to read as follows:

97-XX-XX   AlliedSignal Inc.: Amendment 39-XXXX. Docket 97-ANE-03. 
Supersedes AD 88-24-07, Amendment 39-6062.

    Applicability: AlliedSignal Inc. (formerly AiResearch and 
Garrett) TSCP700-4B and -5 auxiliary power units (APUs), with first 
stage low pressure compressor (LPC) disks, Part Number (P/N) 
3606429-1, installed on but not limited to Airbus A300 series, and 
McDonnell Douglas DC-10 and KC-10 (military) 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 (e) 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 first stage LPC disk rim separation due to low cycle 
fatigue, which could result in an uncontained APU failure and damage 
to the aircraft, accomplish the following:
    (a) Remove from service first stage LPC disks, P/N 3606429-1, in 
accordance with the schedule derived from calculations in paragraph 
C.(3) of AlliedSignal Service Bulletin (SB) No. TSCP700-49-7266, 
dated June 16, 1996, and the removal procedures described in the 
Accomplishment Instructions of that SB, and replace with serviceable 
parts.
    (b) Except as provided in paragraph (a), this AD establishes a 
life limit of 8,000 cycles since new (CSN) for first stage LPC 
disks, P/N 3606429-1.
    (c) The definition of a disk cycle may be found in the 
applicable AlliedSignal Inc. APU Component Maintenance Manual.
    (d) Except as provided in paragraph (e) of this AD, no 
alternative replacement times may be approved for first stage LPC 
disks, P/N 3606429-1.
    (e) 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. Operators shall submit their requests 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.


[[Page 49429]]


    (f) 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.
    (g) The actions required by this AD shall be done in accordance 
with the following AlliedSignal Inc. SB:

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            Document No.              Pages              Date           
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TSCP700-49-7266....................      1-6  June 16, 1996.            
Total pages: 6.                                                         
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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.
    (h) This amendment becomes effective on October 27, 1997.

    Issued in Burlington, Massachusetts, on September 12, 1997.
Mark C. Fulmer,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 97-24910 Filed 9-19-97; 8:45 am]
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