AD 2007-01-09 Airworthiness Directives; Boeing Model 747-100B SUD, 747-200B, 747-300, 747-400, 747-400D, and 747SP Series Airplanes

Models named: 747-100B SUD, 747-200B, 747-300, 747-400, 747-400D, 747SP series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Boeing Model 747-100B SUD, 747-200B, 747-300, 747-400, 747-400D, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2591, dated April 6, 2006.

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 Detailed Inspections and Related Investigative and Corrective Actions (f) Perform a detailed inspection for cracking of the crease beam and adjacent intercostals, stringers, frames, and skin panels at the applicable initial and repetitive compliance times specified in Table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2591, dated April 6, 2006; except, where the alert service bulletin specifies an initial compliance time after the date on the alert service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. Do all applicable related investigative and corrective actions before further flight if any cracking is found. Do all applicable actions in accordance with the Accomplishment Instructions of the alert service bulletin, except as provided by paragraphs (f)(1) and (f)(2) of this AD. (1) Where the alert service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, before further flight, repair those conditions using a method approved in accordance with paragraph (g) of this AD. (2) Where the alert service bulletin specifies to report certain information to the manufacturer, this AD does not include that requirement. Alternative Methods of Compliance (AMOCs) (g)(1) The Manager, Seattle Aircraft Certification Office (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) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. (3) 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 Commercial Airplanes Delegation Option Authorization 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 (h) You must use Boeing Alert Service Bulletin 747-53A2591, dated April 6, 2006, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the 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 December 26, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E7-910 Filed 1-24-07; 8:45 am] BILLING CODE 4910-13-P

This AD results from a report indicating that an operator discovered crease beam cracking on two Model 747 airplanes. We are issuing this AD to detect and correct cracking of the crease beam and adjacent structure, which could become large and result in in-flight depressurization and inability of the airframe structure to sustain flight loads.