AD 2006-03-12

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD requires an inspection for chafing of certain wire bundles located above the center fuel tank, corrective actions if necessary, and replacement of wire bundle clamps with new clamps. This AD also requires an inspection for damage to the fuel vapor barrier area located below the wire bundles, and corrective action if necessary. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent chafed wire bundles near the center fuel tank, which could cause electrical arcing through the tank wall and ignition of fuel vapor in the fuel tank, and result in a fuel tank explosion.

Final rule.

2006-03-12 Boeing: Amendment 39-14476. Docket No. FAA-2005-20354; Directorate Identifier 2004-NM-166-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective March 16, 2006. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to all Boeing Model 737-100, -200, -200C, - 300, -400, and -500 series airplanes, certificated in any category. \n\nUnsafe Condition \n\n\t(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent chafed wire bundles near the center fuel tank, which could cause electrical arcing through the tank wall and ignition of fuel vapor in the fuel tank, and result in a 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\nInspection of Wire Bundles and Fuel Vapor Barrier and Corrective Actions \n\n\t(f) Within 60 months after the effective date of this AD: Do a detailed inspection for chafing of the wire bundles located below the passenger compartment, above the center fuel tank, aft of station 540 to approximately station 663.75, right buttock line (RBL) and left buttock line (LBL) 24.50; do a detailed inspection for damage to the fuel vapor barrier area located below the wire bundles, as applicable; and do any applicable corrective actions; by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 737-28-1208, Revision 1, dated August 25, 2005. Any corrective actions must be done before further flight. \n\n\tNote 1: For the purposes of this AD, a detailed inspection is: "An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required." \n\nAdjustment/Replacement of Wire Bundle Clamps and Installation of Protective Sleeve \n\n\t(g) After performing the actions required by paragraph (f) of this AD: Before further flight, adjust and replace, as applicable, the wire bundle clamps located aft of station 540; and install a protective sleeve on the upper bundle of the bundle run at station 616, RBL and LBL 24.50; by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 737-28-1208, Revision 1, dated August 25, 2005. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(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. \n\n\t(2) Before using any AMOC approved in accordance with Sec. 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. \n\nMaterial Incorporated by Reference \n\n\t(i) You must use Boeing Service Bulletin 737-28-1208, Revision 1, dated August 25, 2005, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

Examining the Docket \n\n\tYou may 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 street address stated in the ADDRESSES section. \n\nDiscussion \n\n\tThe FAA issued a supplemental notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That supplemental NPRM was published in the Federal Register on December 1, 2005 (70 FR 72083). That supplemental NPRM proposed to require an inspection for chafing of certain wire bundles located above the center fuel tank, corrective actions if necessary, and replacement of wire bundle clamps with new clamps. That supplemental NPRM also proposed to require an inspection for damage to the fuel vapor barrier area located below the wire bundles and, corrective action if necessary. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comment received. The commenter supports the supplemental NPRM. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD as proposed in the supplemental NPRM. \n\nCosts of Compliance \n\n\tThere are about 2,871 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD. \n\n\tEstimated Costs \n\n\nAction \nWork hours \nAverage labor rate per hour \nParts \nCost per airplane \nNumber of U.S.-\nregistered airplanes \nFleet cost \nInspection \n2 \n$65 \nNone \n$130 \n1,042 \n$135,460. \n\n\n\n\n\n\n\n\n\n\n\n\n\n\nReplacementof wire bundle clamps and installation of protective sleeve \n5 \n$65 \n$688 or $1,245 depending on applicable kit. \n$1,013 or $1,570 \n1,042 \nBetween $1,055,546 and \n$1,635,940. \n\nAuthority for This Rulemaking \n\n\tTitle 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. \n\n\tWe 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. \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 and placed it in the AD docket. 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\nSec. 39.13 (Amended) \n\n2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):