Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
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.
We must receive comments on this proposed AD by May 2, 2005.
Use one of the following addresses to submit comments on this proposed AD.
- DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
- Government-wide rulemaking Web site: Go to http://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 http://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.Start Further Info
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.End Further Info End Preamble Start Supplemental Information
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 http://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 http://dms.dot.gov.
Examining the Docket
You can examine the AD docket on the Internet at http://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.
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. Start Printed 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.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 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.
(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.
(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.
(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.
(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.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 05-5137 Filed 3-15-05; 8:45 am]
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