[Federal Register: November 18, 2002 (Volume 67, Number 222)]
[Proposed Rules]
[Page 69493-69494]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18no02-11]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-295-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 777-200 and 777-300 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 777-200 and
777-300 series airplanes. This proposal would require application of
high-temperature sealant to the strut aft dry bay. This action is
necessary to prevent leakage of hydraulic fluid into the strut aft dry
bay, where high temperatures associated with the adjacent primary
exhaust nozzle may ignite the fluid, resulting in an uncontrolled fire
in the strut aft dry bay. This action is intended to address the
identified unsafe condition.
DATES: Comments must be received by January 2, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-295-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays. Comments may be submitted via fax to (425) 227-1232.
Comments may also be sent via the Internet using the following address:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2001-NM-295-AD'' in the subject line and need not
be submitted in triplicate. Comments sent via the Internet as attached
electronic files must be formatted in Microsoft Word 97 for Windows or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: John Vann, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone
(425) 227-1024; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
Submit comments using the following format:
[sbull] Organize comments issue-by-issue. For example, discuss a
request to change the compliance time and a request to change the
service bulletin reference as two separate issues.
[sbull] For each issue, state what specific change to the proposed
AD is being requested.
[sbull] Include justification (e.g., reasons or data) for each
request.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2001-NM-295-AD.'' The postcard will be date stamped
and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 2001-NM-295-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report indicating that one operator had
found coked hydraulic fluid in the strut aft dry bay, which is located
directly above the primary exhaust nozzle. Investigation revealed that
hydraulic fluid had leaked from the strut aft fairing through an
unsealed gap between the strut aft bulkhead, the diagonal brace
fitting, and the cowl fairing. This unsealed gap, if not corrected,
permits leakage of hydraulic fluid into the strut aft dry bay, where
high temperatures associated with the adjacent primary exhaust nozzle
may ignite the fluid. The result would be an uncontrolled fire in the
strut aft dry bay, which lacks fire detection or fire extinguishing
equipment.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
777-54A0016, dated January 25, 2001, which describes procedures for
application of high temperature sealant to fill the gap between the
strut aft bulkhead, the diagonal brace fitting, and the aft cowl
fairing. Accomplishment of the actions specified in the service
bulletin is intended to adequately address the identified unsafe
condition.
[[Page 69494]]
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require accomplishment of the actions specified in
the service bulletin described previously.
Cost Impact
There are approximately 298 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 95 airplanes of U.S. registry
would be affected by this proposed AD, that it would take approximately
4 work hours per airplane to accomplish the proposed application of
sealant, and that the average labor rate is $60 per work hour. Required
materials would cost approximately $20 per airplane. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $24,700, or $260 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this proposed AD were not adopted. The cost impact
figures discussed in AD rulemaking actions represent only the time
necessary to perform the specific actions actually required by the AD.
These figures typically do not include incidental costs, such as the
time required to gain access and close up, planning time, or time
necessitated by other administrative actions.
The manufacturer may cover the cost of required materials and labor
associated with this NPRM, subject to warranty conditions. As a result,
the costs attributable to the proposed AD may be less than stated
above.
Regulatory Impact
The regulations proposed herein 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. Therefore, it
is determined that this proposal would not have federalism implications
under Executive Order 13132.
For the reasons discussed above, I certify that 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) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 adding the following new
airworthiness directive:
Boeing: Docket 2001-NM-295-AD.
Applicability: Model 777-200 and 777-300 series airplanes having
line numbers 2 through 297 inclusive, 299, and 300; certificated in
any category.
Note 1: This AD applies to each airplane 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 airplanes 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 (b) 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 leakage of hydraulic fluid into the strut aft dry
bay, where high temperatures associated with the adjacent primary
exhaust nozzle may ignite the fluid, resulting in an uncontrolled
fire in the strut aft dry bay; accomplish the following:
Application of Sealant
(a) Within 1,000 flight hours after the effective date of this
AD: Apply high-temperature sealant to the strut aft dry bays, in
accordance with Boeing Alert Service Bulletin 777-54A0016, dated
January 25, 2001.
Alternative Methods of Compliance
(b) 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, Seattle Aircraft Certification
Office (ACO), FAA. Operators shall submit their requests through an
appropriate FAA Principal Maintenance Inspector, who may add
comments and then send it to the Manager, Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(c) 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 airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on November 8, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 02-29117 Filed 11-15-02; 8:45 am]
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