AD 2004-24-07

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires replacing the bracket for the wire bundle of the fuel quantity indicating system (FQIS), performing a general visual inspection of the FQIS wire bundle for damage, and doing corrective actions if necessary. This AD is prompted by a report of an incorrectly installed FQIS wire bundle. We are issuing this AD to prevent chafing of the FQIS wire(s) in the center fuel tank, which, when combined with a lightning strike or a power wire short to the FQIS wire(s), could result in arcing in the center fuel tank and consequent fuel tank explosion.

Final rule.

2004-24-07 Boeing: Amendment 39-13883. Docket No. FAA-2004-18562; Directorate Identifier 2003-NM-147-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective January 3, 2005. \n\nAffected ADs \n\n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, as listed in Boeing Special Attention Service Bulletin 737-28-1190, Revision 1, dated March 27, 2003; certificated in any category. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by a report of an incorrectly installed fuel quantity indicating system (FQIS) wire bundle. We are issuing this AD to prevent chafing of the FQIS wire(s) in the center fuel tank, which, when combined with a lightning strike or a power wire short to the FQIS wire(s), could result in arcing in the center fuel tank and consequent fuel tank explosion. \n\nCompliance \n\n\t(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. \n\nReplacement and Inspection \n\n\t(f) Within 24 months after the effective date of this AD, replace the bracket for the FQIS wire bundle with a new, improved bracket, perform a general visual inspection of the FQIS wire bundle for damage, and perform any applicable corrective actions, by accomplishing all of the actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-28- 1190, Revision 1, dated March 27, 2003. Do any applicable corrective actions before further flight. \n\n\tNote 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." \n\nActions Accomplished in Accordance With Previous Issue of Service Bulletin \n\n\t(g) Actions accomplished before the effective date of this AD in accordance with Boeing Special Attention Service Bulletin 737-28- 1190, dated January 16, 2003, are considered acceptable for compliance with the corresponding action specified in this AD. \n\nParts Installation \n\n\t(h) As of the effective date of this AD, no person may install a bracket, part number 287A9111-3, for the FQIS wire bundle, on any airplane. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i) 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.Material Incorporated by Reference \n\n\t(j) You must use Boeing Special Attention Service Bulletin 737- 28-1190, Revision 1, dated March 27, 2003, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of the document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. \n\n\tYou may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR part 39 with an AD for certain Boeing Model 737-600, -700, -700C, -800, and - 900 series airplanes. That action, published in the Federal Register on July 8, 2004 (69 FR 41207), proposed to require replacing the bracket for the wire bundle of the fuel quantity indicating system (FQIS), performing a general visual inspection of the FQIS wire bundle for damage, and doing corrective actions if necessary. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD. \n\nAgree With Proposed AD \n\n\tTwo commenters, the Air Line Pilots Association, on behalf of its members, and the manufacturer, generally agree with the proposed AD. \n\nRequest To Reduce Compliance Time \n\n\tOne commenter, the Civil Aviation Authority, which is the airworthiness authority for the United Kingdom, requests reducing the compliance time specified in paragraph (f) of the proposed AD. The proposed compliance time is "within 24 months after the effective date of this AD." The commenter notes that Boeing issued Special Attention Service Bulletin 737-28-1190, dated January 16, 2003, over a year and a half ago. The commenter contends that the compliance time in the proposed AD should be reduced to ensure the prevention of a chaffed wire in the fuel tank. \n\n\tWe do not agree to reduce the compliance time in the final rule. In developing an appropriate compliance time, we considered the safety implications, parts availability, and maintenance schedules that would allow for timely accomplishment and minimal fuel tank entries. Minimizing fuel tank entries reduces the potential for unintended hazardous conditions. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the required actions can be done in a timely manner within the fleet, while still maintaining an adequate level of safety. Operators are always permitted to accomplish the requirements of an AD at a time earlier than the specified compliance time. If additional data are presented that would justify a shorter compliance time, we may consider further rulemaking on this issue. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are about 1,063 airplanes of the affected design in the worldwide fleet. This AD will affect about 518 airplanes of U.S. registry. \n\n\tReplacing the bracket will take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Required parts will cost about $186 per airplane. Based on these figures, we estimate the cost of the required replacement on U.S. operators to be $130,018, or $251 per airplane. \n\n\tInspecting the FQIS wire bundle will take approximately 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, we estimate the cost of the required inspection on U.S. operators to be $33,670, or $65 per airplane. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action" under Executive Order 12866; \n\n\t(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t(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. \n\n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):