Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes, 12815-12816 [05-5137]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 70, Number 50 (Wednesday, March 16, 2005)]
[Proposed Rules]
[Pages 12815-12816]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-5137]



[[Page 12815]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20626; Directorate Identifier 2004-NM-243-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 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 737-600, -700, -700C, -800, and -900 series 
airplanes. This proposed AD would require replacing the fuel shutoff 
valve wires and conduit assemblies in the left and right engine strut 
aft fairing areas. This proposed AD is prompted by a report that an 
operator discovered many small chafe marks and exposed shield braid on 
fuel shutoff wires routed through a conduit in the wing. We are 
proposing this AD to prevent exposed wires that could provide an 
ignition source in a flammable leakage zone and possibly lead to an 
uncontrolled fire or explosion.

DATES: We must receive comments on this proposed AD by May 2, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, 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, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
https://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This 
docket number is FAA-2005-20626; the directorate identifier for this 
docket is 2004-NM-243-AD.

FOR FURTHER INFORMATION CONTACT: Doug Pegors, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6504; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20626; 
Directorate Identifier 2004-NM-243-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that website, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit https://dms.dot.gov.

Examining the Docket

    You can examine the AD docket on the Internet at https://
dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received a report that an operator discovered many small 
chafe marks and exposed shield braid on fuel shutoff valve wires routed 
through a conduit in the wing of a Boeing Model 737-700 series 
airplane. Most of the chafing occurred at each bend of the conduit, 
although chafing was also found at the conduit end fitting. 
Investigation revealed that high vibration causes wire movement in the 
conduit which can lead to chafing. If sharp edges are present inside 
the conduit, chafing can result in damage to the wire jacket and can 
expose the shield braid. This condition, if not corrected, could result 
in exposed wires that could provide an ignition source in a flammable 
leakage zone and possibly lead to an uncontrolled fire or explosion.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 737-28-
1199, dated September 9, 2004. The service bulletin describes 
procedures for replacing the fuel shutoff valve wires and conduit 
assemblies in the left and right engine strut aft fairing areas with 
new fuel shutoff valve wires and conduit assemblies. 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. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously.

Costs of Compliance

    There are about 1,338 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 529 airplanes of 
U.S. registry. The proposed actions would take about 42 work hours per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would cost about $2,418 per airplane. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $2,723,292, or 
$5,148 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.

[[Page 12816]]

    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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20626; Directorate Identifier 2004-NM-
243-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by May 2, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800, 
and -900 series airplanes; as listed in Boeing Special Attention 
Service Bulletin 737-28-1199, dated September 9, 2004; certificated 
in any category.

Unsafe Condition

    (d) This AD was prompted by a report that an operator discovered 
many small chafe marks and exposed shield braid on fuel shutoff 
valve wires routed through a conduit in the wing. We are issuing 
this AD to prevent exposed wires that could provide an ignition 
source in a flammable leakage zone and possibly lead to an 
uncontrolled fire or explosion.

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.

Action Heading

    (f) Within 24 months after the effective date of this AD, 
replace the fuel shutoff valve wires and conduit assemblies in the 
left and right engine strut aft fairing areas with new fuel shutoff 
valve wires and conduit assemblies; by accomplishing all the actions 
in the Accomplishment Instructions of Boeing Special Attention 
Service Bulletin 737-28-1199, dated September 9, 2004.

Alternative Methods of Compliance (AMOCs)

    (g) 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.

    Issued in Renton, Washington, on March 8, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-5137 Filed 3-15-05; 8:45 am]
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