AD 2009-09-08 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 747-53A2651, dated June 12, 2008.

Comply with this AD within the compliance times specified, unless already done. Inspection(s) and Corrective Action (f) At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008, except as required by paragraph (i) of this AD, do an external surface high frequency eddy current inspection to detect cracks in the radius detail of the upper lobe doubler on both sides of the airplane, and the applicable corrective action, by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin, except as required by paragraphs (g) and (h) of this AD. The applicable corrective action must be done before further flight. As applicable, repeat the inspection thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008. (g) Where Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008, paragraph 3.B., Work Instructions, PART 3, Step 1, specifies a sealant application “from STA 2520 to STA 2521,” this AD requires a sealant application “from STA 2491 to STA 2521” on both sides of the airplane. (h) Where Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008, specifies to contact Boeing for repair instructions instead of repairing or replacing any cracked upper lobe doubler in accordance with the service bulletin, this AD requires, before further flight, repairing any cracked upper lobe doubler using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (i) Where Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008, 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. Alternative Methods of Compliance (AMOCs) (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590. (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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. (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 (k) You must use Boeing Alert Service Bulletin 747-53A2651, dated June 12, 2008, 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, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com ; Internet https://www.myboeingfleet.com . (3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152. (4) You may also review copies of the service information that is incorporated by reference 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 22, 2009. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E9-9925 Filed 5-6-09; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports of cracks in the radius detail of the upper lobe doublers. We are issuing this AD to detect and correct cracks in the upper lobe doublers. Such cracks could result in significant degradation of the fuselage structure and reduce its ability to carry flight loads from the vertical stabilizer, which could adversely affect the controllability of the airplane.