2008-10-07: Fuel tank systems

2008-10-07 Boeing: Amendment 39-15513. Docket No. FAA-2007-28385; Directorate Identifier 2006-NM-181-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective June 12, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to all Boeing Model 747-100, 747-100B, 747- 100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, certificated in any category. \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 (k) 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 a design review of the fuel tank systems. We are issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane. \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\nService Information Reference \n\n\t(f) The term "Revision March 2008 of Document D6-13747-CMR," as used in this AD, means Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-CMR, Revision March 2008. (For the purposes of Revision March 2008 of Document D6-13747-CMR, the Model 747SR series airplane is basically a Model 747-100 series airplane with certain modifications to improve fatigue life.) \n\nMaintenance Program Revision \n\n\t(g) Before December 16, 2008, revise the FAA-approved maintenance program to incorporate the information in Section D, "AIRWORTHINESS LIMITATIONS--SYSTEMS," AWLs No. 28-AWL-01 through No. 28-AWL-19 inclusive, of Revision March 2008 of Document D6- 13747-CMR; except that the initial inspections required by paragraph (h) of this AD must be done at the applicable compliance time specified in that paragraph. As an optional action, AWLs No. 28-AWL- 20 through No. 28-AWL-23 inclusive, as identified in Section D of Revision March 2008 of Document D6-13747-CMR, also may be incorporated into the FAA-approved maintenance program. Accomplishing the revision in accordance with a later revision of Document D6-13747-CMR is an acceptable method of compliance if the revision is approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. \n\nInitial Inspections and Repair if Necessary \n\n\t(h) Do the inspections specified in Table 1 of this AD at the compliance time specified in Table 1 of this AD, and repair any discrepancy, in accordance with Section D of Revision March 2008 of Document D6-13747-CMR. The repair must be done before further flight. Accomplishing the actions required by this paragraph in accordance with a later revision of Document D6-13747-CMR is an acceptable method of compliance if the revision is approved by the Manager, Seattle ACO. Accomplishing the inspections identified in Table 1 of this AD as part of an FAA-approved maintenance program before the applicable compliance time specified in Table 1 of this AD constitutes compliance with the requirements of this paragraph. \n\n\tNote 2: 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\n\tNote 3: For the purposes of this AD, a special detailed inspection is: "An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. The examination is likely to make extensive use of specialized inspection techniques and/or equipment. Intricate cleaning and substantial access or disassembly procedure may be required." \n\n\t\t\t\t\tTable 1.--Initial Inspections\n\n\n\n\n\nCompliance Time\n(whichever occurs later)\n\nAWL No.\n\nDescription\nThreshold\nGrace Period\n28-AWL-01\nA detailed inspection of external wires over the center fuel tank for damaged clamps, wire chafing, and wire bundles in contact with the surface of the center fuel tank\nWithin 144 months since the date of issuance ofthe original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness\nWithin 72 months after the effective date of this AD\n28-AWL-03\nA special detailed inspection of the lightning shield to ground termination on the out-of-tank fuel quantity indicating system to verify functional integrity\nWithin 144 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness\nWithin 24 months after the effective date of this AD\n28-AWL-13\nA special detailed inspection of the fault current bond of the fueling shutoff valve actuator of the center wing tank to verify electrical bond\nWithin 144 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness\nWithin 60 months after the effective date of this AD\n\n\nNo Alternative Inspections, Inspection Intervals, or Critical Design Configuration Control Limitations (CDCCLs) \n\n\t(i) After accomplishing the actions specified in paragraphs (g) and (h) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are part of a later revision of Revision March 2008 of Document D6-13747-CMR that is approved by the Manager, Seattle ACO; or unless the inspections, intervals, or 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 Revisions of the Service Information \n\n\t(j) Actions done before the effective date of this AD in accordance with Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), D6-13747- CMR, Revision March 2006; Revision May 2006; Revision December 2006; Revision January 2007; Revision September 2007; or Revision January 2008; are acceptable for compliance with the corresponding requirements of paragraphs (g) and (h) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(k)(1) The Manager, Seattle ACO, 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) 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(l) You must use Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-CMR, Revision March 2008, to do the actions required by this AD, unless the AD specifies otherwise. \n\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\n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. \n\n\t(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or 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.