AD 2009-06-20

We are adopting a new airworthiness directive (AD) for certain Boeing Model 757-200, 757-200PF, and 757-300 series airplanes. This AD requires, for certain airplanes, measuring the electrical bond resistance at certain stations and doing any applicable repair; installing support brackets for the hot short protector and new support clamps for the wire bundles; installing the equipment of the hot short protector; and modifying an existing wire bundle and installing a new wire bundle. This AD also requires, for certain other airplanes, measuring the electrical bond resistance at certain stations, measuring the electrical bonding resistance between the hot short protector and rear spar web, and doing any applicable repair. This AD also requires revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent the center fuel tank densitometer fromoverheating and becoming a potential ignition source inside the fuel tank, which, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane.

Final rule.

2009-06-20 Boeing: Amendment 39-15857. Docket No. FAA-2008-0846; Directorate Identifier 2008-NM-045-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective April 28, 2009. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 757-200, 757-200PF, and 757- 300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 757-28A0085, Revision 2, dated December 11, 2007. \n\n\tNote 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance (AMOC) according to paragraph (m) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane. \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 the center fuel tank densitometer from overheating and becoming a potential ignition source inside the fuel tank, which, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane. \n\nCompliance \n\n\t(e) Comply with this AD within the compliance times specified, unless already done. \n\nMeasurement, Installation, Modifications, Replacement, and Repair \n\n\t(f) For Groups 1 through 3 airplanes, as identified in Boeing Alert Service Bulletin 757-28A0085, Revision 2, dated December 11, 2007 ("the service bulletin''): Within 60 months after the effective date of this AD, do the measurement, installations, modifications, replacement, and applicable repair by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin. Do the applicable repair before further flight. \n\nMeasure and Repair \n\n\t(g) For Group 4 airplanes, as identified in Boeing Alert Service Bulletin 757-28A0085, Revision 2, dated December 11, 2007 ("the service bulletin''): Within 60 months after the effective date of this AD, do the measurements and applicable repair by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin. Do the applicable repair before further flight. \n\nAirworthiness Limitations (AWLs) Revision for AWL No. 28-AWL-22 \n\n\t(h) Concurrently with accomplishing the actions required by paragraphs (f) and (g) of this AD, revise the AWLs section of the Instructions for Continued Airworthiness (ICA) by incorporating AWL No. 28-AWL-22 of Subsection G of Section 9, D622N001-9 Revision December 2008 of the Boeing 757 MaintenancePlanning Data (MPD) Document. \n\nNo Alternative Critical Design Configuration Control Limitations (CDCCLs) \n\n\t(i) After accomplishing the action specified in paragraph (h) of this AD, no alternative CDCCLs may be used unless the CDCCLs are approved as an AMOC in accordance with the procedures specified in paragraph (k) of this AD. \n\nCredit for Actions Done According to Previous Issues of the Service Information \n\n\t(j) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 757-28A0085, Revision 1, dated April 16, 2007, are acceptable for compliance with the requirements of paragraphs (f) and (g) of this AD. \n\t(k) Actions done before the effective date of this AD in accordance with AWL No. 28-AWL-22 of Subsection G of Section 9 D622N001-9, Revision January 2007, Revision November 2007, or Revision March 2008 of the Boeing 757 Maintenance Planning Data (MPD) Document, are acceptable for compliance with the requirements of paragraph (h) of this AD. \n\nTerminating Action for AWLs Revision \n\n\t(l) Incorporating AWL No. 28-AWL-22 into the AWLs section of the ICA in accordance with paragraph (g)(3) of AD 2008-10-11, amendment 39-15517, terminates the action specified in paragraph (h) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(m)(1) The Manager, Seattle Aircraft Certification Office, FAA, ATTN: Jen Pei, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6409; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. \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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI,your local FSDO. \n\nMaterial Incorporated by Reference \n\n\t(n) You must use Boeing Alert Service Bulletin 757-28A0085, Revision 2, dated December 11, 2007; and Section 9, D622N001-9 Revision December 2008 of the Boeing 757 Maintenance Planning Data (MPD) Document; as applicable; 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 or 425-227-1152. \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\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 757-200, 757-200PF, and 757-300 series airplanes. That NPRM was published in the Federal Register on August 7, 2008 (73 FR 45895). That NPRM proposed to require, for certain airplanes, measuring the electrical bond resistance at certain stations and doing any applicable repair; installing support brackets for the hot short protector and new support clamps for the wire bundles; installing the equipment of the hot short protector; and modifying an existing wire bundle and installing a new wire bundle. That NPRM also proposed to require, for certain other airplanes, measuring the electrical bond resistance at certain stations, measuring the electrical bonding resistance between the hot short protector and rear spar web, and doing any applicable repair. That NPRM also proposed to require revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the two comments received. \n\nSupport for the NPRM \n\n\tBoeing concurs with the NPRM. \n\nRequest to Exempt Cargo-Only Airplanes \n\n\tAir Transport Association, on behalf of one of its members, UPS, proposes that cargo-only airplanes be exempt from installing the hot short protector specified in the NPRM, based on the same reasons used to exclude cargo-only airplanes in Federal Aviation Regulations change, "Reduction of Fuel Tank Flammability in Transport Category Airplanes,'' Docket FAA-2005-22997 (Final Rule issued July 9, 2008, amendment numbers 25-125, 26-2, 121-340, 125-55, and 129-46): \n\tCargo operations are predominately at night when outside temperatures are lower. \n\tCargo operators turn off packs prior to takeoff. \n\tCargo operators have fewer daily flights (2) compared to passenger operators (4-6). \n\tThe cost/benefit does not justify retrofit on current cargo aircraft. \n\tUPS recommends that all cargo-only airplanes currently in operation be exempt from the retrofit/installation portion of the NPRM and service bulletin. UPS is of the opinion that changing the Instructions for Continuing Airworthiness and maintenance programs to perform bonding checks will be sufficient in addressing the potential short issue in existing cargo-only airplanes. UPS does not object to new cargo-only airplanes having the hot short protector installed. \n\tWe do not agree with the request to exempt cargo-only airplanes from the requirements of this AD. Although the fuel tank flammability reduction rule (mentioned previously) provides important safety improvements, it was not intended to address any specific identified unsafe conditions. Instead, that rule provides an additional layer of protection when unidentified and uncorrected fuel tank ignition sources develop. This AD, however, addresses an identified ignition source in the fuel tank system. While the factors mentioned by the operator may reduce the probability that this ignition source will actually cause a fuel tank explosion, they do not justify allowing this known ignition source to continue to exist when practical means exist to eliminate it. We have not changed the AD in this regard. \n\nActions Since NPRM Was Issued \n\n\tWe have reviewed Airworthiness Limitation (AWL) No. 28-AWL-22 of Subsection G of Section 9, D622N001-9 Revision December 2008 of the Boeing 757 Maintenance Planning Data (MPD) Document ("Revision December 2008 of the MPD''). In the NPRM we referred to AWL No. 28-AWL-22 of Revision November 2007 of the MPD. AWL No. 28-AWL-22 has not changed. We have revised paragraph (h) of this AD to refer to AWL No. 28-AWL-22 of Revision December 2008 of the MPD; added paragraph (k) to the AD giving credit for AWL No. 28-AWL-22 done in accordance with Revisions January 2007, November 2007, and March 2008 of the MPD; and re-identified the subsequent paragraphs accordingly. \n\nConclusion \n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. \n\nCosts of Compliance \n\n\tWe estimate that this AD affects 433 airplanes of U.S. registry. 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\nParts1\nCost per product1\nNumber of U.S.-registered airplanes\nFleet cost1\nGroups 1-3; measurement, installations, and modification\n8\n$80\nBetween $14,110 and $14,215\nBetween $14,750 and $14,855\n432\nBetween $6,372,000 to $6,417,360 \nGroup 4; measurements \n2\n$80\nNone\n$160 \n1\n$160\nAWL Revision\n1\n$80\nNone\n$80\n433$34,640\n 1 Depending on airplane configuration. \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 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\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\n 1. 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: