2005-05-18: Webs of the aft pressure bulkhead

2005-05-18 Boeing: Amendment 39-14007. Docket No. FAA-2004-19022; Directorate Identifier 2004-NM-122-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective April 18, 2005. \n\nAffected ADs \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, certificated in any category; as identified in Boeing Service Bulletin 737-53-1251, dated June 3, 2004. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by a report of cracks found, during fatigue testing, at several of the fastener rows in the web lap splices at the dome apex of the aft pressure bulkhead. We are issuing this AD to detect and correct fatigue cracks in the webs of the aft pressure bulkhead, which could result in rapid decompression 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\nInitial and RepetitiveInspections \n\n\t(f) Prior to accumulating 26,000 total flight cycles or within 4,000 flight cycles after the effective date of this AD, whichever occurs later: Do a detailed inspection, low frequency eddy current inspection, and high frequency eddy current inspection of the webs of the aft pressure bulkhead at body station 1016 for cracks, in accordance with Boeing Service Bulletin 737-53-1251, dated June 3, 2004. Repeat the inspections thereafter at intervals not to exceed 4,000 flight cycles. \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\nCorrective Action \n\n\t(g) If any crack is found during any inspection required by paragraph (f) of this AD: Before further flight, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an Authorized Representative for the Boeing Delegation Option Authorization (DOA) Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically reference this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(h)(1) The Manager, Seattle ACO, 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) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\nMaterial Incorporated by Reference \n\n\t(i) You must use Boeing Service Bulletin 737-53-1251, dated June 3, 2004, 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 this 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\t\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.