AD 2010-20-08 Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR Series 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 The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes, certificated in any category, having line numbers 1 through 1419 inclusive; except for Model 747-400 series airplanes that have been modified into the 747-400 large cargo freighter configuration.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Restatement of Requirements of AD 2001-16-02, With New Service Information Repetitive Inspections for Frame Segment Between Stringers 23 and 31 (No Terminating Action) (g) For airplanes having line numbers 1 through 1304 inclusive: Inspect the airplane for cracks between stringers 23 and 31 per Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009; at the later of the times specified in either paragraph (h) or (i) of this AD, per Table 1, as follows. After the effective date of this AD, use only Revision 5 of Boeing Alert Service Bulletin 747-53A2450, to accomplish the required inspection. Table 1— Inspection Requirements Type of inspection Area to inspect (1) Detailed Visual Strap inner chords forward and aft of the web, and exposed web adjacent to the inner chords on station 2231 frame from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable. (2) Surface High Frequency Eddy Current (HFEC) Station 2231 inner chord angles at lower main sill interface per Figure 5 or Figure 6 of the service bulletin, as applicable. (3) Open Hole HFEC Station 2231 frame fastener locations per Figures 4 and 7, and either Figure 5 or 6 of the service bulletin, as applicable. (4) Surface HFEC Around fastener locations on station 2231 inner chords from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable. (5) Low Frequency Eddy Current Station 2231 frame strap in areas covered by the reveal per Figure 5 or Figure 6 of the service bulletin, as applicable. (h) Do the inspections specified in paragraph (g) of this AD at the applicable times specified in paragraph (h)(1) or (h)(2) of this AD. Repeat the inspections at intervals not to exceed 3,000 flight cycles. (1) Do the inspections per Table 1 of this AD at the applicable time specified in the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001. Where the compliance time in the logic diagram specifies a compliance time beginning, “from receipt of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).” (2) After the effective date of this AD, do the inspections per Table 1 of this AD at the applicable compliance time specified in paragraph 1.E., “Compliance” of the Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Where the compliance time in Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001, specifies a compliance time beginning, “after the date on Revision 2 of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).” (i) Within 3,000 flight cycles after accomplishment of the inspections specified in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, dated May 4, 2000; or Revision 1, dated July 6, 2000; repeat the inspections specified in paragraph (g) of this AD at intervals not to exceed 3,000 flight cycles. Note 1: There is no terminating action currently available for the inspections required by paragraph (g) of this AD. Note 2: Where there are differences between the AD and Boeing Alert Service Bulletin 747-53A2450, the AD prevails. New Requirements of This AD Additional Repetitive Inspections (For Frame Segment Between Stringers 16 and 23) (j) For all airplanes: Before the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole high frequency eddy current (HFEC) inspection, a surface HFEC inspection, and a subsurface low frequency eddy current (LFEC) inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 23; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. Note 3: The part number of the nut for fastener code “K” in Figure 7 of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, should be “BACN10JC3CD,” instead of “BACB30JC3CD.” In addition, the part number of the optional nut for this fastener code should be “BACN10YR3CD,” instead of “BACN10YR4CD.” Repetitive Inspections for Line Numbers 1305 and On (For Frame Segment Between Stringers 23 and 31) (k) For airplanes having line numbers 1305 and on: Before 16,000 total flight cycles or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole HFEC inspection, a surface HFEC inspections, and a subsurface LFEC inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 23 and 31; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. Corrective Action (l) If any crack is found during any inspection required by this AD, before further flight, repair the crack in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings; or in accordance with Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD. As of the effective date of this AD, repair the crack using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Post-Repair Inspections (m) Except as required by paragraph (n) of this AD, for airplanes on which the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 31, is repaired in accordance with Boeing Alert Service Bulletin 747-53A2450: Within 3,000 flight cycles after doing the repair or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do the detailed, LFEC, and HFEC inspections of the repaired area for cracks in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. If no cracking is found, repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. If any crack is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Doing the inspections specified in paragraph (m) of this AD terminates the repetitive inspections required by paragraphs (g), (h), (i), (j), and (k) of this AD for the repaired area. (n) For any frame that is repaired in accordance with a method other than the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, do the inspection in accordance with a method approved in accordance with the procedures specified in paragraph (o) of this AD. Alternative Methods of Compliance (AMOCs) (o)(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 Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590; Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov . (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 the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that 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. (4) AMOCs approved previously in accordance with AD 2001-16-02, amendment 39-12370, are approved as AMOCs for the corresponding provisions of paragraphs (g), (h), (i), and (l) of this AD. Material Incorporated by Reference (p) You must use Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, 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. (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 September 15, 2010. Robert D. Breneman, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2010-23840 Filed 10-4-10; 8:45 am] BILLING CODE 4910-13-P

This AD results from additional reports of cracks that have been found in the strap and inner chord of the forward edge frame of the number 5 main entry door cutouts, between stringers 16 and 23. Based on these reports, we have determined that the frame segment between stringers 16 and 23 is also susceptible to the unsafe condition. The Federal Aviation Administration is issuing this AD to detect and correct such cracks. This condition, if not corrected, could cause damage to the adjacent body structure, which could result in depressurization of the airplane in flight.