[Federal Register Volume 76, Number 13 (Thursday, January 20, 2011)]
[Proposed Rules]
[Pages 3566-3569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-1119]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2011-0026; Directorate Identifier 2010-NM-104-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 777-200 and -
300 Series Airplanes Equipped With Pratt and Whitney Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Model 777-200 and -300 series airplanes. This proposed AD would
require repetitive inspections for
[[Page 3567]]
hydraulic fluid contamination of the interior of the strut disconnect
assembly; repetitive inspections for discrepancies of the interior of
the strut disconnect assembly, if necessary; repetitive inspections of
the exterior of the strut disconnect assembly for cracks, if necessary;
and corrective action if necessary. This proposed AD also provides an
optional terminating action for the inspections. This proposed AD
results from reports of system disconnect boxes that have been
contaminated with hydraulic fluid and, in one incident, led to
subsequent cracking of titanium parts in the system disconnect
assembly. We are proposing this AD to detect and correct hydraulic
fluid contamination, which can cause cracking of titanium parts in the
system disconnect assembly, resulting in compromise of the engine
firewall. A cracked firewall can allow fire in the engine area to enter
the strut and can lead to an uncontained engine strut fire if flammable
fluid is present. Cracking of the disconnect box may also reduce the
effectiveness of the fire extinguishing system in the engine
compartment and could contribute to an uncontained engine fire. In
addition, a cracked disconnect box can leak flammable fluids into the
engine core, which can initiate an engine fire, and lead to one or both
fire conditions discussed above.
DATES: We must receive comments on this proposed AD by March 7, 2011.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail [email protected];
Internet https://www.myboeingfleet.com. You may review copies of the
referenced service information at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information
on the availability of this material at the FAA, call 425-227-1221.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
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 Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Kevin Nguyen, Propulsion Branch, ANM-
140S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6501;
fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2011-0026;
Directorate Identifier 2010-NM-104-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because 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 we
receive about this proposed AD.
Discussion
We have received reports of system disconnect boxes that have been
contaminated with hydraulic fluid. One operator has found cracks in the
system disconnect assembly bulkheads and lower skin panel. Subsequent
analysis at Boeing found hydrogen enbrittlement of the system
disconnect assembly bulkheads and lower skin panel. The system
disconnect assembly is made from titanium and is located near the hot
engine core of the engine where temperatures can exceed 270 degrees
Fahrenheit. The presence of hydraulic fluid and temperature above 270
degrees Fahrenheit can result in hydrogen embrittlement of the titanium
system disconnect assembly. Hydrogen embrittlement combined with a high
sonic vibration environment can result in cracking of the system
disconnect assembly. The system disconnect assembly is a box where
hydraulic, fuel, and electrical connections are made between the engine
and the strut. This box acts as a firewall between the engine
compartment and the strut. The engine compartment has a fire
extinguishing system while the strut does not. The strut is considered
a flammable leakage zone where flammable fluids may be present. These
fluids are subsequently drained from the strut and system disconnect
box. A cracked firewall can allow fire in the engine area to enter the
strut and can lead to an uncontained engine strut fire if flammable
fluid is present. Cracking of the disconnect box may also reduce the
effectiveness of the fire extinguishing system in the engine
compartment and could contribute to an uncontained engine fire. In
addition, a cracked disconnect box can leak flammable fluids into the
engine core, which can initiate an engine fire, and lead to one or both
fire conditions discussed above.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 777-54A0024,
Revision 1, dated November 4, 2010. This service bulletin describes
procedures for doing repetitive general visual inspections for
hydraulic fluid contamination of the interior of the strut disconnect
assembly; repetitive detailed inspections for discrepancies (e.g.,
hydraulic fluid coking, heat discoloration, cracks, and etching or
pitting) of the interior of the strut disconnect assembly, if certain
conditions are found; repetitive detailed inspections of the exterior
of the strut disconnect assembly for cracks; and corrective action, if
certain conditions are found. The corrective action is replacing the
titanium system disconnect assembly with an Inconel system disconnect
assembly. If accomplished, the replacement will eliminate the potential
for hydrogen embrittlement and subsequent cracking, and would eliminate
the need for the inspections of the titanium strut disconnect assembly.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or
[[Page 3568]]
develop in other products of these same type designs. This proposed AD
would require accomplishing the actions specified in the service
information described previously.
Costs of Compliance
We estimate that this proposed AD would affect 53 airplanes of U.S.
registry. We also estimate that it would take about 48 work-hours per
product to comply with this proposed AD. The average labor rate is $85
per work-hour. Required parts would cost about $122,617 per product.
Based on these figures, we estimate the cost of this proposed AD to the
U.S. operators to be $6,714,941, or $122,697 per product.
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 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 this proposed
regulation:
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. 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA 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 AD:
The Boeing Company: Docket No. FAA-2011-0026; Directorate Identifier
2010-NM-104-AD.
Comments Due Date
(a) We must receive comments by March 7, 2011.
Affected ADs
(b) None.
Applicability
(c) This AD applies to The Boeing Company Model 777-200 and -300
series airplanes, certificated in any category; equipped with Pratt
and Whitney engines; as identified in Boeing Alert Service Bulletin
777-54A0024, Revision 1, dated November 4, 2010.
Subject
(d) Air Transport Association (ATA) of America Code 54:
Nacelles/Pylons.
Unsafe Condition
(e) This AD results from reports of system disconnect boxes that
have been contaminated with hydraulic fluid, in which one case a
crack was found. The Federal Aviation Administration is issuing this
AD to detect and correct hydraulic fluid contamination, which can
cause cracking of titanium parts in the system disconnect assembly,
resulting in compromise of the engine firewall. A cracked firewall
can allow fire in the engine area to enter the strut and can lead to
an uncontained engine strut fire if flammable fluid is present.
Cracking of the disconnect box may also reduce the effectiveness of
the fire extinguishing system in the engine compartment and could
contribute to an uncontained engine fire. In addition, a cracked
disconnect box can leak flammable fluids into the engine core, which
can initiate an engine fire and lead to one or both fire conditions
discussed above.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Inspections and Corrective Actions
(g) Within 12 months after the effective date of this AD: Do a
general visual inspection for hydraulic fluid contamination of the
interior of the strut disconnect assembly, in accordance with Part 1
of the Accomplishment Instructions of Boeing Alert Service Bulletin
777-54A0024, Revision 1, dated November 4, 2010.
(1) For airplanes on which no hydraulic fluid contamination is
found (Condition 1): Repeat the general visual inspection required
by paragraph (g) of this AD thereafter at intervals not to exceed
6,000 flight cycles or 750 days, whichever occurs first.
(2) For airplanes on which hydraulic fluid contamination is
found (Condition 2): Before further flight, do a detailed inspection
for discrepancies (e.g., hydraulic fluid coking, heat discoloration,
cracks, and etching or pitting) of the interior of the strut
disconnect assembly, in accordance with Part 2 of the Accomplishment
Instructions of Boeing Alert Service Bulletin 777-54A0024, Revision
1, dated November 4, 2010.
(i) For airplanes on which no discrepancy is found during the
inspection required by paragraph (g)(2) of this AD (Condition 2A):
Repeat the detailed inspection required by paragraph (g)(2) of this
AD thereafter at intervals not to exceed 6,000 flight cycles or 750
days, whichever occurs first.
(ii) For airplanes on which hydraulic fluid coking or heat
discoloration is found but no cracking, etching, or pitting is found
during the inspection required by paragraph (g)(2) of this AD
(Condition 2B): Do the actions required by paragraph (g)(2)(ii)(A)
and (g)(2)(ii)(B) of this AD.
(A) Within 300 flight cycles after doing the inspection required
by paragraph (g)(2) of this AD: Do a detailed inspection of the
exterior of the strut disconnect assembly for cracks, in accordance
with Part 3 of the Accomplishment Instructions of Boeing Alert
Service Bulletin 777-54A0024, Revision 1, dated November 4, 2010;
and repeat the detailed inspection thereafter at intervals not to
exceed 300 flight cycles.
(B) Within 6,000 flight cycles or 750 days after hydraulic fluid
coking and/or heat discoloration was found during the inspection
required by paragraph (g)(2) of this AD, whichever occurs first:
Replace the titanium system disconnect assembly with an Inconel
system, in accordance with Part 4 of the Accomplishment Instructions
of Boeing Alert Service Bulletin 777-54A0024, Revision 1, dated
November 4, 2010.
(h) For airplanes on which any crack, etching, or pitting is
found during any inspection required by paragraph (g)(2) or
(g)(2)(ii)(A) of this AD (Condition 3): Before further flight,
replace the titanium system disconnect assembly with an Inconel
system, in accordance with Part 4 of the Accomplishment Instructions
of Boeing Alert Service Bulletin 777-54A0024, Revision 1, dated
November 4, 2010.
Optional Terminating Action
(i) Replacing the titanium system disconnect assembly with an
Inconel system
[[Page 3569]]
disconnect assembly in accordance with Part 4 of the Accomplishment
Instructions of Boeing Alert Service Bulletin 777-54A0024, Revision
1, dated November 4, 2010, terminates the actions required by this
AD.
Credit for Actions Accomplished in Accordance With Previous Service
Information
(j) Actions accomplished before the effective date of this AD
according to Boeing Alert Service Bulletin 777-54A0024, dated April
1, 2010, are considered acceptable for compliance with the
corresponding actions specified in this AD.
Alternative Methods of Compliance (AMOCs)
(k)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
ATTN: Kevin Nguyen, Propulsion Branch, ANM-140S, FAA, Seattle
Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (425) 917-6501; fax (425) 917-6590.
Information may be e-mailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
Issued in Renton, Washington, on January 12, 2011.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2011-1119 Filed 1-19-11; 8:45 am]
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