AD 2005-06-11 Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD, -200B, and -300 Series Airplanes; and Model 747SR and 747SP Series Airplanes

Models named: 747-100, -100B, -100B SUD, -200B, -300 series, 747SR, 747SP 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, and -300 series airplanes; and Model 747SR and 747SP series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. New Initial Compliance Time (f) At the earlier of the times specified in paragraphs (f)(1) and (f)(2) of this AD, do the actions specified in paragraph (h) of this AD. (1) Before the accumulation of 28,000 total flight cycles, or within 60 days after March 15, 2000 (the effective date of AD 2000-04-17, amendment 39-11600), whichever occurs later. (2) Before the accumulation of 18,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later. Determining Number of Flight Cycles for Compliance Time (g) For the purposes of calculating the compliance threshold for the actions required by paragraph (f) of this AD, all pressurized flight cycles, including the number of flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less, must be counted when determining the number of flight cycles that have occurred on the airplane. Where the service bulletin and this AD differ, the AD prevails. Requirements of AD 2000-04-17 and New Repair Method (h) At the time specified in paragraph (f) of this AD, perform the actions required by either paragraph (h)(1) or (h)(2) of this AD. After any inspection, operators may conduct the subsequent inspection using the alternate inspection method provided that its corresponding repetitive inspection interval is used, rather than the interval for the previous inspection method. (1) Gain access to the upper deck floor beams from above the upper deck floor, and perform an open-hole high frequency eddy current (HFEC) inspection to detect cracking of the upper deck floor beams at BS 340 and 360, and on both the left and right sides of the floor beam at BS 380 between buttock lines (BL) 40 and 76; in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002. (i) If no cracking is found, perform the actions required by paragraph (h)(1)(i)(A), (h)(1)(i)(B), or (h)(1)(i)(C) of this AD, in accordance with the alert service bulletin. (A) Repeat the inspection required by paragraph (h)(1) of this AD at intervals not to exceed 3,000 flight cycles. (B) Modify (oversize) the floor panel attachment fastener holes as specified in Figure 5 of the alert service bulletin, and repeat the inspection required by paragraph (h)(1) of this AD within 10,000 flight cycles. Repeat the inspection at intervals not to exceed 3,000 flight cycles. (C) Do the applicable repair procedures shown in Part 3 of the Accomplishment Instructions of the alert service bulletin; except where the alert service bulletin specifies to contact Boeing for appropriate action, before further flight, repair in accordance with paragraph (h)(1)(ii)(A) of this AD. (ii) If any cracking is found, before further flight, do the action specified in either paragraph (h)(1)(ii)(A) or (h)(1)(ii)(B) of this AD. (A) Repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate; or in accordance with data meeting the certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) or Authorized Representative (AR) for the Boeing Delegation Option Authorization (DOA) who has been authorized by the Manager, Seattle ACO to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD. (B) Repair in accordance with Part 3 of the Accomplishment Instructions of the alert service bulletin; except where the alert service bulletin specifies to contact Boeing for appropriate action, before further flight, repair in accordance with paragraph (h)(1)(ii)(A) of this AD. (2) Gain access to the upper deck floor beams from below the upper deck floor; and perform a surface HFEC inspection to detect cracking of the floor beams at BS 340 and 360, and on both the left and right sides of the floor beam at BS 380 between BL 40 and 76; in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002. (i) If no cracking is found, repeat the inspection required by paragraph (h)(2) of this AD at intervals not to exceed 750 flight cycles. (ii) If any cracking is found, before further flight, do the action specified in paragraph (h)(1)(ii) of this AD. New Post-Repair Inspection (i) For areas repaired in accordance with paragraph (h)(1)(i)(C) or (h)(1)(ii)(B) of this AD: Before the accumulation of the applicable threshold specified in the “New Inspection Threshold” column in Table 1 of Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002, after accomplishing the repair; or within 1,000 flight cycles after the effective date of this AD; whichever occurs later: Do the actions specified in paragraphs (i)(1) through (i)(3) of this AD, as applicable. (1) For locations that have been repaired by oversizing the fastener holes only ( i.e. , repair strap and/or clip not installed) as shown in Part 3 of the Accomplishment Instructions of Revision 1 or 2 of the alert service bulletin: Perform an open-hole HFEC inspection to detect cracking of the upper deck floor beams, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002. (2) For locations previously repaired as shown in Figure 8 of Revision 1 or 2 of the alert service bulletin: Do an open-hole HFEC inspection to detect cracks at the fastener holes of the floor panel attachment and the inboard and outboard end fastener locations common to the repair strap, in accordance with Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002. (3) For locations previously repaired as shown in Figure 9 or Figure 10 of Revision 1 or 2 of the alert service bulletin: Do a surface HFEC inspection to detect cracks at the upper chord along the edge of the trimmed surface; and perform an open-hole HFEC inspection to detect cracks at the fastener holes of the floor panel attachment and the inboard and outboard end fastener locations common to the repair strap, in accordance with Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002. (j) If no crack is detected during any inspection required by paragraphs (i)(1) through (i)(3) of this AD, repeat the applicable inspection thereafter at intervals not to exceed 3,000 flight cycles. (k) If any crack is detected during any inspection required by paragraph (i)(1) through (i)(3) of this AD, before further flight, do the action specified in paragraph (h)(1)(ii)(A) of this AD. (l) For areas repaired in accordance with paragraph (h)(1)(ii)(A) of this AD that do not have a post-repair inspection program approved by the Manager, Seattle ACO, or according to data meeting the certification basis of the airplane approved by an AR for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make those findings: Do the actions specified in paragraph (h) of this AD at the time specified in that paragraph. Credit for Previous Released Alert Service Bulletin (m) Actions accomplished before the effective date of this AD per Boeing Alert Service Bulletin 747-53A2431, dated February 10, 2000; or Revision 1, dated March 8, 2001; are acceptable for compliance with the applicable requirements of this AD. Alternative Methods of Compliance (AMOCs) (n)(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 an AR for the Boeing DOA 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. (3) AMOCs, approved previously per AD 2000-14-17, amendment 39-11600, are approved as AMOCs with paragraph (h)(1)(ii)(A) of this AD, provided that a post-repair inspection program has been approved by the Manager, Seattle ACO, or by a Boeing Company Designated Engineering Representative or an AR for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make those findings. Material Incorporated by Reference (o) You must use Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002, 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 March 9, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-5386 Filed 3-18-05; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by the results of an additional detailed analysis that indicate fatigue cracks can initiate sooner than has previously been observed. We are issuing this AD to prevent failure of the upper deck floor beams at certain body stations (BS) due to fatigue cracking, which could result in rapid decompression and reduced controllability of the airplane.