[Federal Register Volume 74, Number 69 (Monday, April 13, 2009)]
[Proposed Rules]
[Pages 16811-16812]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-8311]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2009-0247; Directorate Identifier 2009-NE-07-AD]
RIN 2120-AA64
Airworthiness Directives; Hamilton Sundstrand Power Systems T-
62T-46C12 Auxiliary Power Units
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for Hamilton Sundstrand Power Systems T-62T-46C12 auxiliary power units
(APUs). This proposed AD would require upgrading the software in the
APU full-authority digital controller (FADEC), from software version
02.01.000 to version 03.00.000. This proposed AD results from two
reports of APU compartment explosions due to over-fueling of the APU at
low rpm during the start sequence. We are proposing this AD to prevent
over-fueling of the APU during the start sequence, which could lead to
fuel explosions, injury, and damage to the APU and the airplane.
DATES: We must receive any comments on this proposed AD by June 12,
2009.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
FOR FURTHER INFORMATION CONTACT: Roger Pesuit, Aerospace Engineer, Los
Angeles Aircraft Certification Office, FAA, Transport Airplane
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712; e-mail:
[email protected]; telephone (562) 627-5251, fax (562) 627-5210.
Contact Hamilton Sundstrand Technical Publications, One Hamilton
Road, Mail Stop: 1A-3-Z63, Windsor Locks, CT 06096-1010; telephone
(860) 654-3575, for a copy of the service information identified in
this proposed AD.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2009-0247; Directorate
Identifier 2009-NE-07-AD'' in the subject line of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of the proposed AD. We will consider
all comments received by the closing date and may amend the proposed AD
in light of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact
with FAA personnel concerning this proposed AD. Using the search
function of the Web site, anyone can find and read the comments in any
of our dockets, including, if provided, the name of the individual who
sent the comment (or signed the comment on behalf of an association,
business, labor union, etc.). You may review the DOT's complete Privacy
Act Statement in the Federal Register published on April 11, 2000 (65
FR 19477-78).
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Operations office (telephone (800) 647-5527) is
the same as the Mail address provided in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
Discussion
We received two reports of APU compartment explosions of Hamilton
Sundstrand Power Systems T-62T-46C12 APUs, related to attempted start
of the APU. In both events, the APU compartment was damaged, and the
compartment doors were blown off the airplane. The APUs are ground
operational only, and the airplanes were parked at the time of
explosion. Investigation has revealed that the APU could receive an
excessively rich fuel mixture at low rpm during the start sequence, due
to the APU FADEC version 02.01.000 software, that can allow over-
fueling of the APU during starting. This condition, if not corrected,
could result in over-fueling of the APU during the start sequence,
which could lead to fuel explosion, injury, and damage to the APU and
the airplane.
Relevant Service Information
We have reviewed and approved the technical contents of Hamilton
Sundstrand Power Systems Service Bulletin No. 4503067-49-12, Revision
1, dated December 23, 2008, that describes procedures for upgrading the
APU FADEC software to version 03.00.000. This upgrade eliminates the
potential for over-fueling the APU during the start sequence.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other products
of this same type design. We are proposing this AD, which would require
upgrading the APU FADEC software to version 03.00.000. The proposed AD
would require you to use the service information described previously
to perform these actions.
Costs of Compliance
We estimate that this proposed AD would affect 59 Hamilton
Sundstrand Power Systems T-62T-46C12 APUs installed on airplanes of
U.S. registry. We also estimate that it would take about three work-
hours per APU to perform the proposed actions, and that the average
labor rate is $80 per work-hour. There is no required part cost. Based
on these figures, we estimate the total cost of the proposed AD to U.S.
operators to be $14,160.
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,
[[Page 16812]]
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 have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed AD:
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. Would 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 regulatory evaluation of the estimated costs to
comply with this proposed AD. 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, Incorporation by
reference, Safety.
The Proposed Amendment
Under the authority delegated to me by the Administrator, the
Federal Aviation Administration proposes to amend 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. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive:
Hamilton Sundstrand Power Systems: Docket No. FAA-2009-0247;
Directorate Identifier 2009-NE-07-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by June 12,
2009.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Hamilton Sundstrand Power Systems T-62T-
46C12 auxiliary power units (APUs). These APUs are installed on, but
not limited to, Bombardier Inc. DHC-8-400 series airplanes.
Unsafe Condition
(d) This AD results from two reports of APU compartment
explosions due to over-fueling of the APU at low rpm during the
start sequence. We are issuing this AD to prevent over-fueling of
the APU during the start sequence, which could lead to fuel
explosion, injury, and damage to the APU and 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.
Software Upgrade of the APU Full-Authority Digital Electronic
Controller (FADEC)
(f) At the next FADEC removal, but no later than 18 months after
the effective date of this AD, upgrade the software in the APU FADEC
from software version 02.01.000 to version 03.00.000, and change the
FADEC part number (P/N) from 4503069E to 4503069F.
(g) Use paragraphs 3.A through 3.F.(2) of the Accomplishment
Instructions of Hamilton Sundstrand Power Systems Service Bulletin
No. 4503067-49-12, Revision 1, dated December 23, 2008, to do the
software upgrade and the FADEC P/N change.
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) Contact Roger Pesuit, Aerospace Engineer, Los Angeles
Aircraft Certification Office, FAA, Transport Airplane Directorate,
3960 Paramount Blvd., Lakewood, CA 90712; e-mail:
[email protected]; telephone (562) 627-5251, fax (562) 627-5210,
for more information about this AD.
(j) Contact Hamilton Sundstrand Technical Publications, One
Hamilton Road, Mail Stop: 1A-3-Z63, Windsor Locks, CT 06096-1010;
telephone (860) 654-3575, for a copy of the service information
referenced in this AD.
Issued in Burlington, Massachusetts, on April 7, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E9-8311 Filed 4-10-09; 8:45 am]
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