[Federal Register: December 4, 2007 (Volume 72, Number 232)]
[Proposed Rules]
[Page 68106-68107]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04de07-21]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 68106]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-0267; Directorate Identifier 2007-NM-245-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-400 and 747-400D
Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 747-400 and 747-400D series airplanes. This
proposed AD would require a general visual inspection of the power
feeder wire bundle of the auxiliary power unit (APU) where it crosses
the hydraulic system 4 return tube to determine if parts are installed
to provide separation between the wire bundle and hydraulic tube. This
proposed AD would also require related investigative and corrective
actions if necessary. This proposed AD results from a report that the
power feeder wire bundle of the APU was found touching the hydraulic
system return tube during inspection of an airplane. We are proposing
this AD to prevent insufficient clearance between the wire bundle and
hydraulic tube that could lead to chafing of the wire bundle, which
could cause arcing and a consequent hydraulic fluid fire in an area
outside of the smoke detection and fire extinguishing zone; this
condition could result in an uncontrolled fire on the airplane.
DATES: We must receive comments on this proposed AD by January 18,
2008.
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 AD, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
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: Georgios Roussos, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; 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-2007-0267;
Directorate Identifier 2007-NM-245-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 a report indicating that the power feeder wire
bundle of the auxiliary power unit (APU) was found touching the
hydraulic system return tube during inspection of an in-production
Boeing Model 747-400 series airplane. Boeing subsequently surveyed
several in-service airplanes and found that most of the airplanes had
less than the allowable minimum clearance between the wire bundle and
hydraulic tube. The wire bundle and hydraulic tube are installed in the
aft bulk cargo compartment above the ceiling lining, in an area outside
of the smoke detection and fire extinguishing zone. Insufficient
clearance between the wire bundle and hydraulic tube could lead to
chafing of the wire bundle, which could cause arcing and a consequent
hydraulic fluid fire. This condition, if not corrected, could result in
an uncontrolled fire on the airplane.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 747-24-
2257, Revision 1, dated August 2, 2007. The service bulletin describes
procedures for doing a general visual inspection of the power feeder
wire bundle of the APU where it crosses the hydraulic system 4 return
tube to determine if parts are installed to provide separation between
the wire bundle and hydraulic tube. The service bulletin also describes
procedures for doing related investigative actions and corrective
actions if necessary. The related investigative actions include the
following actions:
Measuring the clearance between the wire bundle and
hydraulic tube to ensure that the clearance is a minimum of 0.5 inch,
if the wire bundle is clamped directly above the hydraulic tube.
Doing a general visual inspection for damage to the wire
bundle where it crosses the hydraulic tube, if two loop clamps and a
spacer are installed to provide separation, if a plastic tie strap and
mount and loop clamp are installed to provide separation, or if no
parts are installed to provide separation.
Doing a general visual inspection for damage to the
hydraulic tube where the wire bundle crosses the hydraulic
[[Page 68107]]
tube, if the wire bundle is found damaged. The corrective actions
include the following actions:
Adjusting the position of the wire bundle to maximize its
separation from the hydraulic tube, if the clearance is less than 0.5
inch.
Removing any parts installed to provide separation between
the wire bundle and hydraulic tube.
Repairing the damaged wire bundle.
Repairing the damaged hydraulic tube or replacing it with
a new hydraulic tube.
Installing a tetrafluoroethylene sleeve on the wire bundle
and attaching the wire bundle and hydraulic tube with two loop clamps
and a spacer.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
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 airplanes
of this same type design. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously.
Costs of Compliance
There are about 462 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 61 airplanes of
U.S. registry. The proposed inspection would take about 1 work hour per
airplane, at an average labor rate of $80 per work hour. Based on these
figures, the estimated cost of the proposed AD for U.S. operators is
$4,880, or $80 per airplane.
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 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
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.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-0267; Directorate Identifier 2007-NM-
245-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by January
18, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-400 and 747-400D series
airplanes, certificated in any category; as identified in Boeing
Special Attention Service Bulletin 747-24-2257, Revision 1, dated
August 2, 2007.
Unsafe Condition
(d) This AD results from a report that the power feeder wire
bundle of the auxiliary power unit (APU) was found touching the
hydraulic system return tube during inspection of an airplane. We
are issuing this AD to prevent insufficient clearance between the
wire bundle and hydraulic tube that could lead to chafing of the
wire bundle, which could cause arcing and a consequent hydraulic
fluid fire in an area outside of the smoke detection and fire
extinguishing zone; this condition could result in an uncontrolled
fire on 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.
Inspection and Related Investigative and Corrective Actions
(f) Within 24 months after the effective date of this AD, do a
general visual inspection of the power feeder wire bundle of the APU
where it crosses the hydraulic system 4 return tube to determine if
parts are installed to provide separation between the wire bundle
and hydraulic tube, and do all the related investigative and
corrective actions as applicable, by accomplishing all of the
actions specified in the Accomplishment Instructions of Boeing
Special Attention Service Bulletin 747-24-2257, Revision 1, dated
August 2, 2007. The related investigative and corrective actions
must be accomplished before further flight after the inspection.
Credit for Actions Done According to Previous Issue of Service Bulletin
(g) Actions done before the effective date of this AD in
accordance with Boeing Special Attention Service Bulletin 747-24-
2257, dated May 18, 2006, are acceptable for compliance with the
corresponding requirements of paragraph (f) of this AD.
Alternative Methods of Compliance (AMOCs)
(h)(1) The Manager, Seattle Aircraft Certification Office, FAA,
has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
Issued in Renton, Washington, on November 23, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-23460 Filed 12-3-07; 8:45 am]
BILLING CODE 4910-13-P