AD 2005-04-51 Airworthiness Directives; Boeing Model 747-100B SUD, -200B, -200C, -200F, and -300 Series Airplanes

Models named: 747-100B SUD, -200C, -200F, -300 series, 747-200B series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 747-100B SUD, -200C, -200F, and -300 series airplanes, line numbers 1 through 685 inclusive; and Boeing Model 747-200B series airplanes, line numbers 271, 276, 336, 344, 369, 389, 397, 474, 491, 518, 521, and 539; certificated in any category.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Repetitive External Detailed Inspections (f) Before the accumulation of 8,000 total flight cycles, or within 10 flight cycles after the effective date of this AD, whichever occurs later, do an external detailed inspection for cracked skin or loose or missing fasteners of the body skin between BS 420 and 460 inclusive and between stringers S-8 and S-12 inclusive on the left and right sides of the airplane. Repeat the external detailed inspection thereafter at intervals not to exceed 25 flight cycles. Note 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.” Corrective Actions (g) If any cracked skin or loose or missing fastener is detected during any external detailed inspection required by paragraph (f) of this AD, before further flight, do a surface high frequency eddy current (HFEC) inspection for cracks in the frames at BS 420, 440, and 460 between stringers S-8 and S-12 on the left and right sides of the airplane, in accordance with paragraph 2. and Notes 2 and 3 of Figure 17 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2265, Revision 9, dated February 17, 2005, except as provided by Note 1 of Figure 17 of the service bulletin. Accomplishing the surface HFEC inspection ends the repetitive inspections required by paragraph (f) of this AD. (1) If no cracked frame is found, before further flight, repair the cracked skin and replace the loose or missing fasteners with new fasteners, as applicable, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the certification basis of the airplane approved by an Authorized Representative (AR) 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 repair must meet the certification basis of the airplane, and the approval must specifically reference this AD. (2) If any cracked frame is found, before further flight, repair the cracked frame and skin and replace the loose or missing fasteners with new fasteners, as applicable, in accordance with a method approved by the Manager, Seattle ACO, FAA; or in accordance with data meeting the certification basis of the airplane approved by an AR 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 reference this AD. Terminating Action (h) Modification in Zone 2 in accordance with Boeing Service Bulletin 747-53-2272, dated January 12, 1987, through Revision 18, dated May 16, 2002, constitutes terminating action for the requirements of this AD. Note 2: Paragraph H. of AD 91-11-01, amendment 39-6997 refers to Boeing Service Bulletin 747-53-2272, dated January 12, 1987, as the appropriate source of service information for accomplishing the optional terminating action in that AD. AD 90-06-06, amendment 39-6490, refers to Boeing Service Bulletin 747-53-2272, Revision 12, dated December 22, 1988; or earlier revisions; as an appropriate source of service information for accomplishing the mandatory terminating action in that AD. Alternative Methods of Compliance (AMOCs) (i)(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. (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 AR 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. Material Incorporated by Reference (j) You must use Boeing Alert Service Bulletin 747-53A2265, Revision 9, dated February 17, 2005, to perform the high frequency eddy current inspections that are required by this AD. 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. You can review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; 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 . Issued in Renton, Washington, on February 25, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-4246 Filed 3-3-05; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by reports of large cracks common to fuselage frames in the upper deck area and severed or nearly severed adjacent frames. We are issuing this AD to detect and correct fatigue cracks in the frames and body skin at body stations (BS) 420, 440, and 460 between stringers S-8 and S-12 inclusive, which could lead to severed frames, and consequent rapid decompression and loss of the structural integrity of the airplane.