AD 2005-01-03 Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 Series Airplanes; and Model 747SP and 747SR Series Airplanes; Equipped With Pratt & Whitney JT9D-3 and -7 (Except -70) Series Engines or General Electric CF6-50 Series Engines With Modified JT9D-7 Inboard Struts

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

This AD applies to Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 series airplanes; and Model 747SP and 747SR series airplanes; certificated in any category; equipped with Pratt & Whitney JT9D-3, and -7 (except -70) series engines or General Electric CF6-50 series engines with modified JT9D-7 inboard struts; as listed in Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Compliance Times (f) Within 18 months after the effective date of this AD, do the actions in paragraphs (g) and (h) of this AD, as applicable. Repeat the actions thereafter at intervals not to exceed 1,200 flight cycles. Inboard Strut Midspar Inspection (g) For Group 1 and 2 airplanes specified in paragraph 1.A.1. of Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003: Perform a detailed inspection of the midspar web of the inboard struts for cracking, disbonding, or buckling; a detailed inspection of the midspar stiffeners for any crack or fracture; related investigative actions; and any applicable corrective actions; in accordance with “Part 1” of the Work Instructions of Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003; except as required by paragraph (i) of this AD. Perform any related investigative actions and any applicable corrective actions before further flight. Outboard Strut Midspar Inspection (h) For Group 1 airplanes specified in paragraph 1.A.1. of Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003: Perform a detailed inspection of the midspar web of the outboard struts for cracking, disbonding, or buckling; a detailed inspection of the midspar stiffeners for any crack or fracture; related investigative actions; and any applicable corrective actions; in accordance with “Part 2” of the Work Instructions of Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003; except as required by paragraph (i) of this AD. Perform any related investigative actions and any applicable corrective actions before further flight. Contact the FAA/Designated Engineering Representative (DER) (i) Where Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003, specifies to contact Boeing for appropriate action: Before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD. Alternative Methods of Compliance (AMOCs) (j)(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 a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. Material Incorporated by Reference (k) You must use Boeing Alert Service Bulletin 747-54A2219, dated September 4, 2003, 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. You 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. Issued in Renton, Washington, on December 27, 2004. Kevin M. Mullin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-105 Filed 1-4-05; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by reports of cracking in the midspar web. We are issuing this AD to detect and correct cracking in the midspar assembly, which could result in the loss of the midspar assembly load path, and could, combined with the loss of the nacelle station 180 bulkhead load path, lead to the separation of the engine from the airplane.