94-13-06: Tension Ties

94-13-06 BOEING: Amendment 39-8946. Docket 93-NM-189-AD. \n\n\tApplicability: Model 747 series airplanes, as listed in Boeing Service Bulletin 747-53-2371, dated July 29, 1993; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent rapid decompression of the airplane due to failure of two or more tension ties, accomplish the following: \n\n\t(a)\tPrior to the accumulation of 1,000 flight cycles after the effective date of this AD, unless accomplished previously within the last 2,000 flight cycles, perform a detailed visual inspection to detect cracking of the outboard end tension ties, in accordance with Boeing Service Bulletin 747-53-2371, dated July 29, 1993. \n\n\t\t(1)\tIf no cracking is detected, repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles until the repair or modification required by paragraph (a)(2) of this AD is accomplished. \n\n\t\t(2)\tIf any cracking is detected, prior to furtherflight, repair or modify the cracked tension tie in accordance with the service bulletin. Accomplishment of this repair or modification terminates the repetitive inspection requirement of paragraph (a) of this AD. \n\n\tNOTE 1: Although AD 84-19-01, amendment 39-4913, requires inspections of the tension ties at body station (BS) 760 on a certain group of Model 747 series airplanes, and at BS 780 on certain other Model 747 series airplanes, the inspections required by this AD do not retract the inspection requirements of that AD. \n\n\t(b)\tPrior to the accumulation of 10,000 flight cycles following repair or modification of any tension tie in accordance with paragraph (a)(2) of this AD, perform a detailed visual inspection to detect cracking of the repaired or modified outboard end tension tie in accordance with Boeing Service Bulletin 747-53-2371, dated July 29, 1993. \n\n\t\t(1)\tIf no cracking is detected, repeat this inspection thereafter at intervals not to exceed 6,000 flight cycles. \n\n\t\t(2)\tIf any cracking is detected, prior to further flight, repair or modify in accordance with the service bulletin, and repeat the inspection required by paragraph (b) of this AD. \n\n\t(c)\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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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(d)\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(e)\tThe inspections, repair, and modification shall be done in accordance with Boeing Service Bulletin 747-53-2371, including the "ADDENDUM," dated July 29, 1993. 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(f)\tThis amendment becomes effective on July 27, 1994.