[Federal Register Volume 69, Number 44 (Friday, March 5, 2004)]
[Proposed Rules]
[Pages 10357-10359]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-4931]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-323-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, 737-700, 737-
700C, 737-800, and 737-900 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 737-600, 737-
700, 737-700C, 737-800, and 737-900 series airplanes. For certain 
airplanes, this proposal would require installation of screws and 
spacers to secure the wire bundles for the aft fuel boost pumps of the 
main fuel tanks. For certain other

[[Page 10358]]

airplanes, this proposal would require a general visual inspection of 
the wire bundles to determine if the wire bundles are clamped, and/or 
if they are damaged; further investigation, as applicable; repair of 
any damage; and installation of applicable brackets, clamps, and 
spacers to secure the wire bundles. This action is necessary to prevent 
electrical arcing in a fuel leakage zone, which could result in an 
uncontrolled fire. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by April 19, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-323-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-323-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 or 2000 or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplanes, 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: Doug Pegors, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington; telephone (425) 917-
6504; fax (425) 917-6590.

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:
     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.
     For each issue, state what specific change to 
the proposed AD is being requested.
     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 2002-NM-323-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. 2002-NM-323-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of chafing of the insulation 
on the wire bundles that supply power to the aft boost pumps on the 
main fuel tanks of certain Boeing Model 737 series airplanes. The 
chafing occurred during deployment of the main landing gear (MLG), when 
an unsupported length of the wire bundle was buffeted by airflow and 
chafed rapidly against the adjacent rear spar stiffeners. The chafed 
wires arced when they came in contact with the rear spar stiffener, 
which shut down the number 1 or 2 main tank aft boost pump. This 
chafing was noted on airplanes that had accumulated as few as two and 
as many as 3,987 total flight hours. This condition, if not corrected, 
could result in electrical arcing in a fuel leakage zone, which could 
result in an uncontrolled fire.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-28A1148, Revision 2, dated December 18, 2003. For certain 
airplanes, this service bulletin describes procedures for installing 
screws and spacers to secure the applicable wire bundles for the aft 
fuel boost pumps of the main fuel tanks.
    For certain other airplanes, this service bulletin describes 
procedures for performing an inspection for chafing or other damage; 
corrective actions (repair of the wire bundle), if necessary; and 
installation of a new, bracket, clamp, and spacers.
    For certain other airplanes, this service bulletin describes 
procedures for performing an inspection to determine if a clamp secures 
the wire bundles. If the wire bundle is not clamped, this service 
bulletin describes procedures for a related investigative action (for 
chafing or damage of the wire bundle); and for corrective actions. For 
these airplanes, the corrective actions include repair of any chafed or 
damaged wire bundles; and installation of a bracket, clamp, and 
spacers, as applicable, to secure the wire bundles.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

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 1,284 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 527 airplanes of U.S. 
registry would be affected by this proposed AD. The work hours and 
required parts per airplane vary according to the configuration group 
to which the affected airplane belongs.
    The following table shows the estimated cost impact for airplanes 
affected by this proposed AD:

[[Page 10359]]



                                               Table--Cost Impact
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                                                               Work hours   Labor cost   Parts cost   Total cost
                Airplane configuration group                      per          per          per          per
                                                                airplane     airplane     airplane     airplane
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1, 2, 3 and 4 on which the actions described in the initial             3         $195         $292         $485
 Service Bulletin have not been accomplished................
1, 2, 3 and 4 on which the actions described in the initial             2         $130           $3         $133
 Service Bulletin have been accomplished; 5, 6, and 7.......
----------------------------------------------------------------------------------------------------------------

    The cost impact figures discussed above are 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.

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 2002-NM-323-AD.

    Applicability: Model 737-600, 737-700, 737-700C, 737-800, and 
737-900 series airplanes, as listed in Boeing Alert Service Bulletin 
737-28A1148, Revision 2, dated December 18, 2003; certificated in 
any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent electrical arcing in a fuel leakage zone, which could 
result in an uncontrolled fire, accomplish the following:

Service Bulletin References

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
28A1148, Revision 2, dated December 18, 2003.

Inspection, Installation, and Corrective Actions

    (b) For airplanes listed in the service bulletin as Groups 1, 2, 
3, and 4 on which Boeing Alert Service Bulletin 737-28A1148, dated 
September 14, 2000, has been accomplished; or for airplanes listed 
in the service bulletin as Groups 5, 6 and 7: Within six months 
after the effective date of this AD, install screws and spacers to 
secure the applicable wire bundles for the aft fuel boost pumps of 
the main fuel tanks. Perform all actions per the service bulletin.
    (c) For airplanes listed in the service bulletin as Groups 1 and 
2 on which Boeing Alert Service Bulletin 737-28A1148, dated 
September 14, 2000, has not been accomplished: Within six months 
after the effective date of this AD, perform a general visual 
inspection of the applicable wire bundles for the aft fuel boost 
pumps of the main fuel tanks for chafing or other damage. Perform 
any applicable corrective action; and install a new bracket clamp, 
and spacers to secure the wire bundles; prior to further flight. 
Perform all actions per the service bulletin.
    (d) For airplanes listed in the service bulletin as Groups 3 and 
4 on which Boeing Alert Service Bulletin 737-28A1148, dated 
September 14, 2000, has not been accomplished: Within six months 
after the effective date of this AD, perform a general visual 
inspection of the applicable wire bundles for the aft fuel boost 
pumps of the main fuel tanks to determine if the wire bundle is 
secured with a clamp; and perform any related investigative action, 
and any applicable corrective actions, prior to further flight. 
Perform all actions per the service bulletin.

    Note 1:
    For the purposes of this AD, a general visual inspection is 
defined as: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
enhance visual access to all exposed surfaces in the inspection 
area. This level of inspection is made under normally available 
lighting conditions such as daylight, hangar lighting, flashlight, 
or droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

Actions Accomplished Per Previous Issue of the Service Bulletin

    (e) Action accomplished before the effective date of this AD per 
Boeing Alert Service Bulletin 737-28A1148, Revision 1, dated August 
22, 2002, are considered acceptable for compliance with the 
corresponding action specified in this AD.

Alternative Methods of Compliance

    (f) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, is authorized to approve 
alternative methods of compliance (AMOCs) for this AD.

    Issued in Renton, Washington, on February 25, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-4931 Filed 3-4-04; 8:45 am]
BILLING CODE 4910-13-P