AD 2008-09-05 Airworthiness Directives; Boeing Model 747 Airplanes

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

This AD applies to Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-32A2482, dated June 14, 2007.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Service Bulletin (f) The term “service bulletin,” as used in this AD, means Boeing Alert Service Bulletin 747-32A2482, dated June 14, 2007. Initial Inspection for Part Number, Serial Number, and Category (g) Within 18 months after the effective date of this AD, inspect the pad-up area on the forward upper inboard surface of the trunnion fork assembly of both the left and right wing landing gears to determine the part number and serial number and to determine the category of the trunnion fork assemblies. A review of airplane maintenance or delivery records is acceptable instead of the inspection if the part number and serial number of the installed fork assembly can be conclusively determined from that review. Do the actions in accordance with the Accomplishment Instructions of the service bulletin. Follow-On Actions for Category A, B, C, or D Trunnion Fork Assemblies (h) If any part number and serial number identified as Category A, B, C, or D in Tables 2 and 3 of paragraph 1.E., “Compliance,” of the service bulletin is found installed during the inspection required by paragraph (g) of this AD: At the applicable compliance time(s) listed in Table 4 or 5 of paragraph 1.E., “Compliance,” of the service bulletin, except as provided by paragraph (i) of this AD, do the applicable action(s) in Table 1 of this AD and applicable related investigative/corrective actions, in accordance with the Accomplishment Instructions of the service bulletin. Table 1.—Requirements for Category A, B, C, or D Trunnion Fork Assemblies For— Do— And— Or— (1) Categories A and C trunnion fork assemblies A detailed inspection for damage to the protective finish and for corrosion of the trunnion fork assembly and a high frequency eddy current (HFEC) inspection to detect cracks (Part 2) An ultrasonic inspection to determine the wall thickness in the area forward of the outer cylinder attach lugs in 8 zones, and a hardness measurement if applicable (Part 3) Do the terminating action (Part 5). (2) Categories B and D trunnion fork assemblies An ultrasonic inspection to determine the wall thickness in the area forward of the outer cylinder attach lugs in 8 zones, and a hardness measurement (Part 3) None None. (i) Where paragraph 1.E., “Compliance,” of the service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. Terminating Action (j) Replacing the trunnion fork assembly of the wing landing gear with a trunnion fork assembly identified in Part 5 of the Accomplishment Instructions of the service bulletin, in accordance with and at the applicable time specified in Table 4 or 5 of paragraph 1.E., “Compliance,” of the service bulletin, constitutes terminating action for the requirements of this AD for that side only. Alternative Methods of Compliance (AMOCs) (k)(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) 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. Material Incorporated by Reference (l) You must use Boeing Alert Service Bulletin 747-32A2482, dated June 14, 2007, to do the actions required by this AD, unless the AD specifies otherwise. (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. (2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. (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 . Issued in Renton, Washington, on April 14, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-8530 Filed 4-21-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from a report of a fractured trunnion fork assembly. We are issuing this AD to prevent a fractured trunnion fork assembly, which could result in the collapse of a wing landing gear on the ground and possible damage to hydraulic equipment and the aileron and spoiler cables. Such damage could result in reduced controllability of the airplane.