93-11-02 BOEING: Amendment 39-8594. Docket 92-NM-230-AD. Supersedes AD 92-19-15, Amendment 39-8373 which superseded AD 88-24-10, Amendment 39-6063. \n\n\tApplicability: Model 707 and 720 series airplanes; line numbers 1 through 906, inclusive; including Model 707 and 720 series airplanes that have been modified in accordance with Supplemental Type Certificates (STC's) SA2699NM, SA3595NM, or SA4015NM; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent separation of an inboard engine from an airplane, accomplish the following: \n\n\t(a)\tPerform a close visual inspection of the midspar fittings to detect cracks in accordance with Boeing Service Bulletin 3183, Revision 4, dated July 8, 1992, unless accomplished previously in accordance with Boeing Service Bulletin 3183, Revision 2, dated January 28, 1988, at the time specified in paragraph (a)(1), (a)(2), (a)(3), or (a)(4), of this AD, as applicable. \n\n\t\t(1)\tFor Model 707-300B/C series airplanes modified by installation of a "hush kit" in accordance with Supplemental Type Certificate (STC) SA2699NM, at the later of the times specified in paragraph (a)(1)(i) or (a)(1)(ii) of this AD: \n\n\t\t\t(i)\tPrior to the accumulation of 12,000 flight hours; or \n\n\t\t\t(ii)\tWithin 650 flight hours or 250 flight cycles after October 8, 1992 (the effective date of AD 92-19-15, Amendment 39-8373), whichever occurs first. \n\n\t\t(2)\tFor Model 707-100B and 720B series airplanes modified by installation of a "hush kit" in accordance with STC SA3595NM or SA4015NM, at the later of the times specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD: \n\n\t\t\t(i)\tPrior to the accumulation of 12,000 flight hours; or \n\n\t\t\t(ii)\tWithin 650 flight hours or 325 flight cycles after October 8, 1992 (the effective date of AD 92-19-15, Amendment 39-8373), whichever occurs first. \n\n\t\t(3)\tFor Model 707-300, 707-400, and 707-300B/C series airplanes, at the later of the times specifiedin paragraph (a)(3)(i) or (a)(3)(ii) of this AD: \n\n\t\t\t(i)\tPrior to the accumulation of 12,000 flight hours; or \n\n\t\t\t(ii)\tWithin 1,100 flight hours or 400 flight cycles after October 8, 1992 (the effective date of AD 92-19-15, Amendment 39-8373), whichever occurs first. \n\n\t\t(4)\tFor Model 707-100, 707-100B, 707-200, 720 and 720B series airplanes, at the later of the times specified in paragraph (a)(4)(i) or (a)(4)(ii) of this AD: \n\n\t\t\t(i)\tPrior to the accumulation of 12,000 flight hours; or \n\n\t\t\t(ii)\tWithin 1,100 flight hours or 550 flight cycles after October 8, 1992 (the effective date of AD 92-19-15, Amendment 39-8373), whichever occurs first. \n\n\t(b)\tRepeat the inspection required by paragraph (a) of this AD thereafter at the intervals specified in paragraph (b)(1), (b)(2), (b)(3), or (b)(4) of this AD, as applicable, in accordance with Boeing Service Bulletin 3183, Revision 4, dated July 8, 1992. \n\n\t\t(1)\tFor Model 707-300B/C series airplanes modified by installation ofa "hush kit" in accordance with STC SA2699NM: At intervals not to exceed 750 flight hours or 300 flight cycles, whichever occurs first. \n\n\t\t(2)\tFor Model 707-100B and 720B series airplanes modified by installation of a "hush kit" in accordance with STC SA3595NM or SA4015NM: At intervals not to exceed 750 flight hours or 375 flight cycles, whichever occurs first. \n\n\t\t(3)\tFor Model 707-300, -400, and -300B/C series airplanes: At intervals not to exceed 1,200 flight hours or 450 flight cycles, whichever occurs first. \n\n\t\t(4)\tFor Model 707-100, 707-100B, 707-200, 720, and 720B series airplanes: At intervals not to exceed 1,200 flight hours or 600 flight cycles, whichever occurs first. \n\n\t(c)\tIf any cracks are found in the midspar support fittings as a result of the inspections required by paragraph (a) or (b) of this AD, prior to further flight: Conduct an eddy current inspection, replace both midspar support fittings, and modify or repair all other structure specified in theservice bulletin, in accordance with Boeing Service Bulletin 3183, Revision 1, dated May 13, 1977, or Revision 2, dated January 28, 1988. If a currently-installed fitting is replaced by a new fitting of the same part number, that new fitting must be inspected in accordance with the compliance times and procedures required by paragraphs (a) and (b) of this AD. \n\n\t(d)\tReplace the midspar fittings with new, improved fittings, in accordance with Boeing Service Bulletin 3183, Revision 2, dated January 28, 1988, at the later of the times specified in paragraph (d)(1) or (d)(2) of this AD. \n\n\t\t(1)\tPrior to the accumulation of 12,000 flight hours; or \n\n\t\t(2)\tWithin 4 years or 4,800 flight cycles after the effective date of this AD, whichever occurs first. \n\n\t(e)\tReplacement of the midspar fittings with new, improved fittings, in accordance with Boeing Service Bulletin 3183, Revision 2, dated January 28, 1988, constitutes terminating action for the inspections required by this AD.(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 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: 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 FAR 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)\tThe inspection, replacement, modification, and repair shall be done in accordance with Boeing Service Bulletin 3183, Revision 1, dated May 13, 1977, or Boeing Service Bulletin 3183, Revision 2, dated January 28, 1988, or Boeing Service Bulletin 3183, Revision 4, dated July 8, 1992. This incorporation by reference 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 October 8, 1992 (57 FR 43890, September 23, 1992). 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 July 6, 1993.