2008-10-15: External skin doublers

2008-10-15 Boeing: Amendment 39-15522. Docket No. FAA-2008-0554; Directorate Identifier 2008-NM-100-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective May 20, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2748, dated May 9, 2008. \n\nUnsafe Condition \n\n\t(d) This AD results from a report of cracked fastener holes at the right stringer 6 (S-6) lap splice between station (STA) 340 and STA 380. We are issuing this AD to detect and correct cracking in the fuselage skin, which could result in rapid decompression and loss of structural integrity. \n\nCompliance \n\n\t(e) Comply with this AD within the compliance times specified, unless already done. \n\nService Bulletin Reference Paragraph \n\n\t(f) The term "alert service bulletin,'' as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2748, dated May 9, 2008. \n\nInspection for Acceptable External Skin Doublers \n\n\t(g) For airplanes identified as Group 1, Configuration 2, in Boeing Alert Service Bulletin 747-53A2748, dated May 9, 2008: At the latest of the times specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, do an external general visual inspection to determine if acceptable external skin doublers are installed at the left- and right-side S-6 lap splices, in accordance with Part 1 of the alert service bulletin. \n\t(1) Prior to the accumulation of 10,000 total flight cycles. \n\t(2) Within 8,000 flight cycles after a modification was done in accordance with Boeing Service Bulletin 747-53-2253. \n\t(3) Within 15 days or 100 flight cycles after the effective date of this AD, whichever occurs first. \n\nAcceptable External Skin Doublers Found at Both Sides \n\n\t(h) If, during the inspection required by paragraph(g) of this AD, acceptable external skin doublers in accordance with the alert service bulletin are found installed at both the left- and right- side S-6 lap splices, no further work is required by this AD. \n\nAcceptable External Skin Doublers Not Found--Repetitive Related Investigative Actions and Corrective Actions \n\n\t(i) If, during the inspection required by paragraph (g) of this AD, acceptable external skin doublers in accordance with alert service bulletin are not found installed at either the left- or right-side S-6 lap splice: Before further flight, do all applicable related investigative and corrective actions by doing all actions specified in Part 2 of the alert service bulletin. Repeat the applicable related investigative actions thereafter at intervals not to exceed 300 flight cycles until the modification specified in paragraph (j) of this AD is done. \n\nOptional Terminating Modification \n\n\t(j) Modifying the airplane by installing acceptable external skin doublers atboth the left- and right-side S-6 lap splices (including doing an open-hole HFEC inspection of the skin for cracking, and trimming out cracking as applicable) in accordance with the alert service bulletin terminates the repetitive related investigative actions required by this AD. \n\n\tNote 1: The alert service bulletin refers to Boeing Service Bulletins 747-53-2253, Revision 3, dated March 24, 1994; and 747-53- 2272, Revision 18, dated May 16, 2002; as additional sources of service information for accomplishment of the modification (installation of acceptable external skin doublers). \n\n\n\tNote 2: AD 90-06-06, amendment 39-6490, requires, among other actions, one of the modification options specified in Boeing Service Bulletin 747-53-2253, dated December 14, 1984. \n\n\tNote 3: AD 90-23-14, amendment 39-6801, requires that inspections of modifications done in accordance with Boeing Service Bulletin 747-53-2253, and applicable repairs, be done in accordance with Boeing Service Bulletin747-53-2253, Revision 2, dated March 29, 1990. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(k)(1) The Manager, Seattle Aircraft Certification Office, FAA, ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. \n\t(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. \n\t(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 CommercialAirplanes 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. \n\nMaterial Incorporated by Reference \n\n\t(l) You must use Boeing Alert Service Bulletin 747-53A2748, dated May 9, 2008, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(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. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. \n\t(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.