AD Amdt-39-13879
Unsafe Condition
Reports of leaks caused by cracked bypass buttons that protruded beyond the internal o-ring seal, leading to a potential fire or explosion from a fuel leak.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install a bracket onto the fuel filter housing assembly to prevent a failed bypass button from protruding beyond the internal o-ring seal. Use specific Alert Service Bulletins (ASBs) for installation instructions. Perform a one-time inspection for proper gap adjustment if brackets were previously installed using certain ASBs.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 500 hours time-in-service or 6 months after the effective date of this AD, whichever occurs earlier.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Hamilton Sundstrand Power Systems Models T-62T-46C12 and T-62T-40C14 (APS 500R) APUs with fuel filter housing assemblies, part numbers 4951627, 4951960, or 4952039, installed. These APUs are installed on, but not limited to, Bombardier DHC-8-400 airplanes and Embraer EMB-135 and -145 series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
The FAA is adopting a new airworthiness directive (AD) for Hamilton Sundstrand Power Systems Models T-62T-46C12 and T-62T-40C14 (APS 500R) APUs with fuel filter housing assembly, part number (P/N) 4951627, 4951960, or 4952039, installed. This AD requires installation of a bracket to prevent a failed bypass button from protruding beyond the internal o-ring seal. This AD results from reports of leaks caused by cracked bypass buttons that protruded beyond the o-ring seal. We are issuing this AD to prevent a fire or explosion caused by a fuel leak from a failed bypass button on the fuel filter housing.
Document Text
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[Federal Register Volume 69, Number 227 (Friday, November 26, 2004)]
[Rules and Regulations]
[Pages 68767-68769]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-25792]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NE-61-AD; Amendment 39-13879 AD 2004-24-03]
RIN 2120-AA64
Airworthiness Directives; Hamilton Sundstrand Power Systems T-62T
Series Auxiliary Power Units (APUs)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Hamilton Sundstrand Power Systems Models T-62T-46C12 and T-62T-40C14
(APS 500R) APUs with fuel filter housing assembly, part number (P/N)
4951627, 4951960, or 4952039, installed. This AD requires installation
of a bracket to prevent a failed bypass button from protruding beyond
the internal o-ring seal. This AD results from reports of leaks caused
by cracked bypass buttons that protruded beyond the o-ring seal. We are
issuing this AD to prevent a fire or explosion caused by a fuel leak
from a failed bypass button on the fuel filter housing.
DATES: This AD becomes effective January 3, 2005. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of January 3, 2005.
ADDRESSES: You can get the service information identified in this AD
from Hamilton Sundstrand Technical Publications Department, P.O. Box
7002, Rockford, IL 61125-7002, U.S.A.
You may examine the AD docket at the FAA, New England Region,
Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA. You may examine the service information, at the FAA,
New England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA; or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
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 proposed airworthiness directive (AD). The proposed AD applies
to Hamilton Sundstrand Power Systems Models T-62T-46C12 and T-62T-40C14
(APS 500R) APUs with fuel filter housing assembly, P/N 4951627,
4951960, or 4952039 installed. We published the proposed AD in the
Federal Register on May 7, 2004 (69 FR 25525). That action proposed to
require installation of a bracket to prevent a failed bypass button
from protruding beyond the internal o-ring seal.
Examining the AD Docket
You may examine the AD Docket (including any comments and service
information), by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. See ADDRESSES for the
location.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Request To Add Alert Service Bulletin Reference
Two commenters request that for APUs Model T-62T-40C14 (APS 500R),
[[Page 68768]]
we add EMBRAER Alert Service Bulletin (ASB) No. 145-49-A027, dated
January 6, 2004, as another means of complying with the AD. We do not
agree. That ASB does not contain instructions for installing the
bracket, but only instructs the operator to use Hamilton Sundstrand ASB
No. ASB-4504112-49-22, for installing the bracket. Because of this, we
have not incorporated by reference that ASB.
Request To Reference the Latest ASB Revision
One commenter requests that we reference the latest revision of
Hamilton Sundstrand ASB No. ASB-4504112-49-22, which is Revision 1,
dated January 5, 2004. The commenter states that the original ASB
specified a gap dimension of 0.32 inch-to-0.65 inch, which is incorrect
and unachievable. ASB Revision 1 corrects the gap dimension to the
proper value of 0.50 inch, plus or minus 0.015 inch. Also, ASB Revision
1 increases the recommended compliance threshold from within 400 hours
time-in-service (TIS) to within 500 hours TIS.
We agree that the latest ASB Revision should be referenced, which
is Revision 2, dated October 4, 2004. The 500 hours TIS threshold is
consistent with EMBRAER ASB No. 145-49-A027, dated January 6, 2004. ASB
Revision 2 requires, as does this AD, that brackets installed using
Hamilton Sundstrand ASB No. ASB-4504112-49-22, Original issue, be
inspected one time for proper gap and adjusted if necessary. ASB
Revision 2 also introduces as an alternative, the installation of a
different part number fuel filter assembly for APU Model T-62-T-40C14,
that is designed to prevent bypass button failure. We have added that
alternative as optional terminating action for APU Model T-62-T-40C14.
We are allowing previous credit for brackets installed using
Hamilton Sundstrand ASB No. ASB-4504112-49-22, Original, dated December
2, 2003, or Revision 1, dated January 5, 2004, before the effective
date of this AD. We have incorporated the changes described previously
in this AD.
Conclusion
We have carefully reviewed the available data, including the
comments received, and determined that air safety and the public
interest require adopting the AD with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
There are about 552 Hamilton Sundstrand APUs of the affected design
in the worldwide fleet. We estimate that 448 APUs installed on
airplanes of U.S. registry will be affected by this AD. We also
estimate that it would take about 1 work hour per APU to perform the
actions, and that the average labor rate is $65 per work hour. Required
parts will cost about $517 per APU. The manufacturer indicated that
they might provide the parts at no cost. Based on these figures, we
estimate the total cost of the AD to U.S. operators to be $260,736.
Regulatory Findings
We have 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 by
sending a request to us at the address listed under ADDRESSES. Include
``AD Docket No. 2003-NE-61-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, 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 (AD):
2004-24-03 Hamilton Sundstrand Power Systems: Amendment 39-13879.
Docket No. 2003-NE-61-AD.
Effective Date
(a) This AD becomes effective January 3, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Hamilton Sundstrand Power Systems Models
T-62T-46C12 and T-62T-40C14 (APS 500R) auxiliary power units (APUs)
with fuel filter housing assemblies, part numbers (P/Ns) 4951627,
4951960, or 4952039, installed. These APUs are installed on, but not
limited to, Bombardier DHC-8-400 airplanes and Empresa Brasileira de
Aeronautica S.A. (EMBRAER) EMB-135 and -145 series airplanes.
Unsafe Condition
(d) This AD results from reports of leaks caused by cracked
bypass buttons that protruded beyond the o-ring seal. We are issuing
this AD to prevent a fire or explosion caused by a fuel leak from a
failed bypass button on the fuel filter.
Compliance
(e) You are responsible for having the actions required by this
AD performed within 500 hours time-in-service or 6 months after the
effective date of this AD, whichever occurs earlier, unless the
actions have already been done.
Installation of Bracket on APU Model T-62T-46C12
(f) Install a bracket onto the fuel filter housing assembly on
APU Model T-62T-46C12. Use 2.A through 2.D of the Accomplishment
Instructions of Hamilton Sundstrand Alert Service Bulletin (ASB) No.
ASB-4503067-49-9, dated December 2, 2003, to install the bracket.
Installation of Bracket on APU Model T-62T-40C14 (APS 500R)
(g) Install a bracket onto the fuel filter housing assembly on
APU Model T-62T-40C14 (APS 500R). Use 2.B. and 2.D.(1) of the
Accomplishment Instructions of Hamilton Sundstrand ASB No. ASB-
4504112-49-22, Revision 2, dated October 4, 2004, to install the
bracket.
Previous Credit
(h) Previous credit is allowed for brackets installed using
Hamilton Sundstrand ASB No. ASB-4503067-49-9, dated December 2,
2003, Hamilton Sundstrand ASB No. ASB-4504112-49-22, Original, dated
December 2, 2003, or Revision 1, dated January 5, 2004, before the
effective date of this AD.
One-Time Inspection for Proper Gap
(i) For brackets previously installed using Hamilton Sundstrand
ASB No. ASB-4504112-49-22, Original, dated December 2, 2003, perform
a one-time inspection for proper gap and if necessary, adjust the
gap between the bracket and bypass button. Use 2.B. and 2.D.(1) of
the Accomplishment
[[Page 68769]]
Instructions of Hamilton Sundstrand ASB No. ASB-4504112-49-22,
Revision 2, dated October 4, 2004 to inspect and adjust the gap.
Optional Terminating Action for APU Model T-62T-40C14 (APS 500R)
(j) For APU Model T-62T-40C14 (APS 500R), installation of a part
number fuel filter assembly that is not listed in this AD
constitutes optional terminating action to the requirements of this
AD.
Alternative Methods of Compliance
(k) 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.
Material Incorporated by Reference
(l) You must use the Alert Service Bulletins listed in Table 1
of this AD to perform the bracket installations required by this AD.
The Director of the Federal Register approved the incorporation by
reference of the documents listed in Table 1 of this AD in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a
copy from Hamilton Sundstrand Technical Publications Department,
P.O. Box 7002, Rockford, IL 61125-7002, U.S.A. You can review copies
at the FAA, New England Region, Office of the Regional Counsel, 12
New England Executive Park, Burlington, MA; or at the National
Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202-741-6030, or go to:
<a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>. Table 1 follows:
Table 1.--Incorporation by Reference
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Page number(s) shown Revision level shown
Alert service bulletin No. on the page on the page Date shown on the page
----------------------------------------------------------------------------------------------------------------
Hamilton Sundstrand ASB-4503067-49- All................. Original............. December 2, 2003.
9.
Hamilton Sundstrand ASB-4504112-49- All................. 2.................... October 4, 2004.
22.
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Related Information
(m) None.
Issued in Burlington, Massachusetts, on November 15, 2004.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 04-25792 Filed 11-24-04; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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