AD 2010-17-03

We are adopting a new airworthiness directive (AD) for certain Model 767-300 series airplanes. This AD requires replacing a wire bundle clamp and installing a tetrafluoroethylene (TFE 2X) sleeve. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent chafing of a wiring bundle, which could result in a high-energy short and, consequently, a possible ignition source in the center auxiliary fuel tank.

Final rule; request for comments.

2010-17-03 The Boeing Company: Amendment 39-16393. Docket No. FAA- 2010-0762; Directorate Identifier 2010-NM-011-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective September 2, 2010. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to The Boeing Company Model 767-300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 767-57A0122, dated October 22, 2009. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 57: Wings. \n\nUnsafe Condition \n\n\t(e) This AD results from fuel system reviews conducted by the manufacturer. The Federal Aviation Administration is issuing this AD to chafing of the wiring bundle, which could result in a high-energy short and, consequently, a possible ignition source in the center auxiliary fuel tank. \n\nCompliance \n\n\t(f) 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\nInstallation \n\n\t(g) Within 60 months after the effective date of this AD, install a tetrafluoroethylene (TFE 2X) sleeve and a wire bundle clamp, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0122, dated October 22, 2009. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(h)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Margaret Langsted, Aerospace Engineer, Propulsion Branch, ANM- 140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6500; fax (425) 917-6590. Information may be e-mailed to: 9-ANM-Seattle-ACO- AMOC-Requests@faa.gov. \n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. \n\nMaterial Incorporated by Reference \n\n\t(i) You must use Boeing Alert Service Bulletin 767-57A0122, dated October 22, 2009, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\t(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http:// www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion \n\n\tThe FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled "Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements'' (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 ("SFAR 88,'' Amendment 21-78, and subsequent Amendments 21-82 and 21-83). \n\tAmong other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources inthe fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews. \n\tIn evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with a latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action. \n\tWe have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. \n\tWe received a report that, during a review of production records, it was found that three airplanes did not receive a tetrafluoroethylene (TFE 2X) sleeve and a clamp as part of an in-production version of the actions required by AD 2009-18-02, Amendment 39-15998 (74 FR 43621, August 27, 2009). The TFE 2X sleeve and the clamp are designed to prevent chafing of a wiring bundle located along a fuel tank boundary structure and to provide additional electrical isolation from the fuel tank. Chafing of that wiring bundle and insufficient electrical isolation, when combined, could result in a high-energy short and, consequently, a potential ignition source in the center auxiliary fuel tank. \n\nRelated Rulemaking \n\n\tAD 2009-18-02 (which applies to certain Model 767-200, -300, -300F, and -400ER series airplanes identified in Boeing Service Bulletins 767- 57A0100, Revision 1, dated June 19, 2008, and 767-57A0102, Revision 1, dated November 27, 2007), requires sealing certain fasteners and stiffeners in the fuel tank, changing certain wire bundle clamp configurations on the fuel tank walls, inspecting certain fasteners in the fuel tanks and to determine the method of attachment of the vortex generators, and corrective action if necessary. \n\nRelevant Service Information \n\n\tWe reviewed Boeing Alert Service Bulletin 767-57A0122, dated October 22, 2009. The service bulletin describes procedures for installing a tetrafluoroethylene (TFE 2X) sleeve and a wire bundle clamp. \n\nFAA's Determination and Requirements of This AD \n\n\tNo airplanes affected by this AD are on the U.S. Register. We are issuing this AD because the unsafe condition described previously is likely to exist or develop on other products of the same type design that could be registered in the United States in the future. This AD requires the actions described in the service bulletin. \n\tSince no airplanes are affected by this AD, notice and opportunity for public comment before issuing this AD are unnecessary. \n\nComments Invited \n\n\tThis AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2010-0762; Directorate Identifier 2010-NM-011-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\tWe will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \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\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 necessaryfor 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\tThis 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\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a "significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and \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\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD docket. \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 FAA amends Sec. 39.13 by adding the following new AD: