95-02-15 BOEING: Amendment 39-9134. Docket 94-NM-27-AD. Supersedes AD 92-07-11, Amendment 39-8207.\n \n\tApplicability: Model 747-100 series airplanes; as listed in Boeing Service Bulletin 747-57A2266, Revision 4, dated November 3, 1994; certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (f) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD. \n\n\tCompliance: Required as indicated, unless accomplished previously.\n \n\tTo prevent fuel leakage onto an engine and a resultant fire, accomplish the following: RESTATEMENT OF ACTIONS REQUIRED BY AD 92-07-11, AMENDMENT 39-8207: \n\n\t(a)\tFor airplanes listed in Boeing Service Bulletin 747-57A2266, dated June 6, 1991, on which the optional terminating action (fastener replacement) specified in the original issue, dated June 6, 1991; Revision 1, dated May 21, 1992; or Revision 2, dated June 10, 1993; of the service bulletin has not been accomplished: Perform a visual inspection and an ultrasonic inspection to detect cracks of the wing front spar web between front spar station (FSS) 636 and FSS 675 in accordance with Boeing Service Bulletin 747-57A2266, dated June 6, 1991; Revision 1, dated May 21, 1992; Revision 2, dated June 10, 1993; or Revision 3, dated March 31, 1994; or Revision 4, dated November 3, 1994; at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable. Repeat these inspections thereafter at intervals not to exceed 2,000 flight cycles until the inspections required by paragraph (b) of this AD are accomplished. \n\n\t\t(1)\tFor airplanes that have accumulated more than 20,000 total flight cycles as of May 4, 1992 (the effective date of AD 92-07-11, amendment 39-8207): Inspect within 6 months after May 4, 1992.\n \n\t\t(2)\tFor airplanes that have accumulated between 15,000 and 20,000 total flight cycles as of May 4, 1992: Inspect within 15 months after May 4, 1992. \n\n\t\t(3)\tFor airplanes that have accumulated less than 15,000 total flight cycles as of May 4, 1992: Inspect within 15 months after accumulating 15,000 total flight cycles. \n\nNEW ACTIONS REQUIRED BY THIS AD: \n\t(b)\tFor airplanes on which the terminating action (fastener replacement) specified in Boeing Service Bulletin 747-57A2266, dated June 6, 1991; Revision 1, dated May 21, 1992; or Revision 2, dated June 10, 1993; has not been accomplished: Prior to the accumulation of 13,000 total flight cycles, or within 9 months after the effective date of this AD, or within 2,000 flight cycles after the immediately preceding inspection accomplished in accordance with paragraph (a) of this AD, whichever occurs later, accomplish the inspections specified in paragraphs (b)(1), (b)(2), and (b)(3) of this AD in accordance with Boeing Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994; or Revision 4, dated November 3, 1994. Repeat these inspections thereafter at intervals not to exceed 2,000 flight cycles. Accomplishment of these inspections terminates the inspections required by paragraph (a) of this AD. After the effective date of this AD, the inspections required by this paragraph shall be accomplished only in accordance with Revision 3 or 4 of the service bulletin. \n\n\t\t(1)\tPerform a detailed visual inspection to detect cracking of the wing front spar chords, stiffeners, and rib posts between the fastener heads between FSS 570 and FSS 684; and \n\n\t\t(2)\tPerform an ultrasonic inspection of the web under the upper and lower chord footprints to detect cracking of the wing front spar web between FSS 570 and FSS 684; and \n\n\t\t(3)\tPerform an ultrasonic inspection of the fasteners in the web-to-chords, and of the fasteners in the top two and bottom two rows in the web-to-stiffeners and web-to-rib posts of the wing front spar to detect cracked or broken fasteners between FSS 570 and FSS 684. \n\n\t(c)\tFor airplanes on which the terminating action (fastener replacement) specified in Boeing Service Bulletin 747-57A2266, dated June 6, 1991; Revision 1, dated May 21, 1992; or Revision 2, dated June 10, 1993; has been accomplished: Within 18 months after accomplishing the terminating action specified in the original issue, Revision 1, or Revision 2 of the service bulletin, or within 9 months after the effective date of this AD, whichever occurs later, accomplish the inspections specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD in accordance with Boeing Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994; or Revision 4, dated November 3, 1994. Repeat these inspections thereafter at intervals not to exceed 2,000 flight cycles. After the effective date of this AD, the inspections required by this paragraph shall be accomplished only in accordance with Revision 3 or 4 of the service bulletin. \n\n\t\t(1)\tPerform a detailed visual inspection of the wing front spar chords, stiffeners, and rib posts between the fastener heads between FSS 570 and FSS 684; and \n\n\t\t(2)\tPerform an ultrasonic inspection of the web under the upper and lower chord footprints to detect cracking of the wing front spar web between FSS 570 and FSS 636 and between FSS 675 and FSS 684; and \n\n\t\t(3)\tPerform an ultrasonic inspection of the fasteners in the web-to-chords, and of the fasteners in the top two rows and bottom two rows in the web-to-stiffeners and web-to- rib posts of the wing front spar to detect cracked or broken fasteners between FSS 570 and FSS 636 and between FSS 675 and 684. \n\n\t(d)\tIf any crack in the web or any cracked or broken fastener is found during any inspection required by this AD, prior to further flight, oversize the fastener hole, perform an eddy current inspection to detect cracks in the fastener hole, and replace the fastener with an oversized fastener, in accordance with Boeing Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994; or Revision 4, dated November 3, 1994. Thereafter, continue to inspect the remaining fasteners in accordance with paragraph (b) or (c) of this AD, as applicable, until the terminating action specified in paragraph (e) of this AD is accomplished. If any crack is found that cannot be removed by oversizing the fastener hole, prior to further flight, repair inaccordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t(e)\tReplacement of the fasteners in the web-to-chords and of the fasteners in the web-to-stiffeners and web-to-rib posts, as specified in Boeing Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994; or Revision 4, dated November 3, 1994; with oversized fasteners on each wing spar in accordance with the service bulletin constitutes terminating action for the repetitive inspections required by paragraph (b) and (c) of this AD. \n\n\t(f)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(g)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(h)\tCertain inspections shall be done in accordance with Boeing Service Bulletin 747-57A2266, dated June 6, 1991, as indicated. The incorporation by reference of this document was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of May 4, 1992 (57 FR 10415, March 26, 1992). Other inspections and replacement actions, as indicated, shall be done in accordance with Boeing Service Bulletin 747-57A2266, Revision 1, dated May 21, 1992; Boeing Service Bulletin 747-57A2266, Revision 2, dated June 10, 1993; Boeing Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994; and Boeing Service Bulletin 747-57A2266, Revision 4, dated November 3, 1994. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(i)\tThis amendment becomes effective on March 23, 1995.