Airworthiness Directives; Hamilton Sundstrand Power Systems (Formerly Sundstrand Power Systems) Auxiliary Power Units Models T-62T-46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A

[Federal Register Volume 70, Number 216 (Wednesday, November 9, 2005)]
[Rules and Regulations]
[Pages 67904-67905]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-22208]



[[Page 67904]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21719; Directorate Identifier 2005-NE-19-AD; 
Amendment 39-14369; AD 2005-23-11]
RIN 2120-AA64


Airworthiness Directives; Hamilton Sundstrand Power Systems 
(Formerly Sundstrand Power Systems) Auxiliary Power Units Models T-62T-
46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Hamilton Sundstrand Power Systems (formerly Sundstrand Power Systems) 
auxiliary power units (APUs) models T-62T-46C2, T-62T-46C2A, T-62T-
46C3, T-62T-46C7, and T-62T-46C7A, with compressor impeller assembly, 
part number (P/N) 4502020 or 4502020A, installed. This AD requires 
removal from service of those compressor impeller assemblies at reduced 
service life limits. This AD results from two reports of uncontained 
failures of compressor impeller assemblies. We are issuing this AD to 
prevent an uncontained APU failure and damage to the airplane.

DATES: This AD becomes effective December 14, 2005.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in Room PL-401 on the plaza level of the Nassif 
Building, 400 Seventh Street, SW., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Roger Pesuit, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone 
(562) 627-5251, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a new AD, applicable to Hamilton Sundstrand Power Systems APUs 
models T-62T-46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-
46C7A, with compressor impeller assembly, part number (P/N) 4502020 or 
4502020A, installed. We published the proposed AD in the Federal 
Register on July 5, 2005 (70 FR 38625). We proposed to require removal 
from service of those compressor impeller assemblies at reduced service 
life limits.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility Docket Offices between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone (800) 
647-5227) is located on the plaza level of the Department of 
Transportation Nassif Building at the street address stated in 
ADDRESSES. Comments will be available in the AD docket shortly after 
the DMS receives them.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We received no comments on the proposal or on 
the determination of the cost to the public.

Conclusion

    We carefully reviewed the available data and determined that air 
safety and the public interest require adopting the AD as proposed.

Costs of Compliance

    About 50 Hamilton Sundstrand Power Systems model T-62T APUs in the 
worldwide fleet are of the affected design. Eight APUs installed on 
airplanes of U.S. registry are affected by this AD. We estimate that it 
will take about 8 work hours to remove and install an APU, and that the 
average labor rate is $65 per work hour. A new or serviceable 
compressor impeller assembly, P/N 4502020 or 4502020A, may be installed 
provided it meets the cycles-since-new criteria in the compliance 
section of this AD. It will take about 55.5 hours to remove and replace 
affected compressor impeller assembly parts. New configuration 
replacement parts for each APU will cost about $36,587. Based on these 
figures, we estimate the total cost of the AD to U.S. operators, to 
remove, upgrade, and install the APUs to be $325,716.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD will not have a substantial direct 
effect 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.
    For the reasons discussed above, I certify that this AD:
    (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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2005-23-11 Hamilton Sundstrand: Amendment 39-14369. Docket No. FAA-
2005-21719; Directorate Identifier. 2005-NE-19-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
14, 2005.

Affected ADs

    (b) None.

[[Page 67905]]

Applicability

    (c) This AD applies to Hamilton Sundstrand Power Systems 
(formerly Sundstrand Power Systems) auxiliary power units (APUs) 
models T-62T-46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-
46C7A, with compressor impeller assembly, part number (P/N) 4502020 
or 4502020A installed. These APUs are installed on, but not limited 
to, BAE Systems AVRO 146, Fokker 50, Saab 2000, and Saab 340 
airplanes.

Unsafe Condition

    (d) This AD results from two reports of uncontained failures of 
compressor impeller assemblies. We are issuing this AD to prevent an 
uncontained APU failure and damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.
    (f) For APUs with compressor impeller assemblies that have 
12,000 or more cycles-since-new (CSN) accumulated on the effective 
date of this AD, remove compressor impeller assemblies from service 
before accumulating 500 additional cycles.
    (g) For APUs with compressor impeller assemblies that have fewer 
than 12,000 CSN on the effective date of this AD, remove compressor 
impeller assemblies from service at or before accumulating 12,500 
CSN.

Alternative Methods of Compliance

    (h) The Manager, Los Angeles Aircraft Certification Office, has 
the authority to approve alternative methods of compliance for this 
AD if requested using the procedures found in 14 CFR 39.19.

Related Information

    (i) Hamilton Sundstrand Service Bulletins No. 4500090-49-33, 
dated January 6, 2005, No. 4500482-49-33, dated January 6, 2005, No. 
4501578-49-22, dated January 13, 2005, No. 4501690-49-47, dated 
November 19, 2005, and No. 4501909-49-16, dated January 13, 2005, 
pertain to the subject of this AD.

    Issued in Burlington, Massachusetts, on November 2, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 05-22208 Filed 11-8-05; 8:45 am]
BILLING CODE 4910-13-P

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