93-05-17 BOEING: Amendment 39-8521. Docket No. 92-NM-10-AD. Supersedes AD 82-08- 09, Amendment 39-4364. \n\n\tApplicability: Applies to Model 707/720, series airplanes, listed in Boeing Service Bulletin 2983, Revision 5, dated January 31, 1991; Model 727 series airplanes listed in Boeing Service Bulletin 727-53-0086, Revision 11, dated August 8, 1991; and Model 737 series airplanes listed in Boeing Service Bulletin 737-53-1023, Revision 11, dated May 16, 1991; certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent depressurization as a result of failure of the control cabin window post structure, accomplish the following: \n\n\t(a)\tInspect the E-F window posts for cracks in accordance with the schedule set forth in Table 1, 2, or 3 of this AD, as applicable: \n\n\n\t\t\t\t\tTABLE 1 \n\n\t\t\tModel 707/720 E-F Window Post Inspection \n\t\t\t(Applicable Boeing Service Bulletin 2983) \n\n\nAirplane\nCondition\nInspection Requiredin accordance with\nRevision 4, 5, or 6\nof Service Bulletin\nInitial\nInspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service Bulletin not accomplished.\nX-ray of E-F window post.\n1,650 after May 21,1982 (effective date of AD 82-08-09), or prior to accumulation of 11,650, whichever \noccurs later. \n3,300 \n2. Repaired or modified per Original Issue of Service Bulletin.\t\nX-ray of E-F window post.\n1,650 after May 21, 1982, or prior to accumulating 10,000 after repair or modification, whichever occurs later.\n3,300 \n3. Repaired or modified per Revision 1, 2, 3, 4, 5, or 6 of Service Bulletin. (Modification was accomplished without using eddy current inspection to verify structure was free of cracks.) \nClose visual for cracks of external doubler and the\texposed portion of the E-F window post with the #2 sliding window open. \n1,650 after May 21, 1982; or prior to accumulating 16,650 after repair or mod- ification; whichever occurs later. \n3,300 \n4. Repaired or modified per Revision 1 of Service Bulletin.\t\nVisual inspection for sufficient edge margin of all of the strap fastener holes. \n1,650 after effective date of this AD. \nNone \n5. Modified per Revision 2, 3, 4, 5, or 6 of Service Bulletin (verified no cracks in structure using eddy current inspection described in Revision 4 or 5 of Service Bulletin).\nClose visual for\tcracks of external doubler and the exposed portion of the E-F window post with the #2 sliding window open. \n3,300 after effective date of this AD, or 24,000 after strap installation, whichever is later. \n3,300 \n\n\t\t\t\t\t TABLE 2 \n\n\t\t\t Model 727 E-F Window Post Inspection\n\t\t\t(Applicable Boeing Service Bulletin 727-53-0086) \n\n\nAirplane\nCondition\nInspection Required\nin accordance with\nRevision 6, 7, 8, 9,10, or 11 of Service Bulletin\nInitial\nInspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service Bulletin not accomplished.\nX-ray of E-F window post.\n1,650 after May 21, 1982 (effective date of AD 82-08-09), or \tprior to accumulation of 11,650, whichever \noccurs later. \n3,300 \n2. Repaired or modified per Original Issue or Revision 1 of Service Bulletin.\nX-ray of E-F window post.\n1,650 after May 21, 1982, or prior to accumulating 10,000 after repair or modification, whichever occurs later.\n3,300 \n3. Repaired or modified per modified per Revision 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 of Service Bulletin. (Modification was accomplished without using eddy current inspection to verify structure was free of cracks.) \nClose visual for\tcracks of external doubler and the exposed portion of the E-F window post with the post with the #2 sliding window open.\n1,650 after May 21, 1982, or prior to accumulating 16,650 after repair or modification, whichever occurs later.\n3,300 \n4. Repaired or modified per Revision 9 or 10 of Service Bulletin.\nVisual inspection for sufficient edge margin of all of the strap fastener holes.\n1,650 after effective date of this AD. \nNone \n5. Modified per Revision 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 of Service Bulletin\t(verified no cracks in structure using eddy current inspection described in Revision 6, 7, 8, 9, 10, or 11).\nClose visual for\tcracks of external doubler and the exposed portion of the E-F window post with the #2 sliding window open. \n3,300 after effective date of this AD, or 24,000 after strap installation, whichever occurs later. \n3,300 \n\n\t\t\t\t\tTABLE 3 \n\t\t\t\tModel 737 E-F Window Post Inspection \n\t\t\t(Applicable Boeing Service Bulletin 737-53-1023) \n\n\nAirplane \nCondition\nInspection Required\nin accordance with\nRevision 6, 7, 8, 9,10, or 11 of Service Bulletin\nInitial Inspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service Bulletin not accomplished.\nX-ray of E-F window post.\n2,750 after May 21, 1982 (effective date of AD 82-08-09), or \tprior to accumulationof 12,750, whichever \noccurs later. \n5,500 \n2. Repaired or modified per Original Issue or Revision 1 or 2 of Service Bulletin.\nX-ray of E-F window post.\n2,750 after May 21, 1982, or prior to accumulating 10,000 after repair or modification, whichever occurs later.\n5,500 \n3. Repaired or modified per modified per Revision 3, 4, 5, 6, 7, 8, 9, 10, or 11 of Service Bulletin. (Modification was accomplished without using eddy current inspection to verify structure was free of cracks.) \nClose visual for\tcracks of external doubler and the exposed portion of the E-F window post with the post with the #2 sliding window open.\n1,650 after May 21, 1982, or prior to accumulating 16,650 after repair or modification, whichever occurs later.\n5,500 \n4. Repaired or modified per Revision 9 or 10 of Service Bulletin.\nVisual inspection for sufficient edge margin of all of the strap fastener holes.\n2,750 after effective date of this AD. \nNone \n5. Modified per Revision 3, 4, 5, 6, 7, 8, 9, 10, or 11 of Service Bulletin\t(verified no cracks in structure using eddy current inspection described in Revision 6, 7, 8, 9, 10, or 11).\nClose visual for\tcracks of external doubler and the exposed portion of the E-F window post with the #2 sliding window open. \n3,300 after effective date of this AD, or 24,000 after strap installation, whichever occurs later. \n5,500 \n\n\t(b)\tInspect the E-N window post for cracks in accordance with the schedule set forth in Table 4, 5, or 6 of this AD, as applicable: \n\n\t\t\t\t\t TABLE 4 \n\n\t\t\t\tModel 707/720 E-N Window Post Inspection \n\t\t\t\t (Applicable Boeing Service Bulletin 2983) \n\n\nAirplane\nCondition\nInspection Required\nin accordance with\nRevision 5 or 6 of Service Bulletin\nInitial\nInspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service\tBulletin not accomplished; or repaired or\t modified per Original Issue or Revision 1, 2, 3, or 4 of Service Bulletin. \nX-ray of E-N windowpost.\n1,650 after effective date of this AD, or prior to the accumulation of 11,650, whichever occurs later. \n3,300\n2. Repaired per Revision 5 or 6 of Service Bulletin (cracks in structure).\t\nX-ray of E-N window post; and close visual of external strap.\t\n1,650 after effective date of this AD, or prior to accumulating 16,650 after repair, whichever occurs later. \n3,300 \n3. Modified per Revision 5 or 6 of Service Bulletin (no cracks in structure).\nX-ray of E-N window post; and close visual of external strap.\n3,300 after effective date of this AD, or 24,000 after strap installation, whichever occurs later. \n6,600 \n \n\t\t\t\t\t TABLE 5 \n\n\t\t\tModel 727 E-N Window Post Inspection \n\t\t (Applicable Boeing Service Bulletin 727-53-0086) \n\n\n\nAirplane\nCondition\nInspection Required\nin accordance with\nRevision 9, 10, or 11 of Service Bulletin\nInitial\nInspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service\tBulletin not accomplished; or repaired or modified per Original Issue or Revision 1, 2, 3, 4, 5, 6, 7, or 8 of Service Bulletin. \nX-ray of E-N window post.\n1,650 after effective date of this AD, or prior to the accumulation of 11,650, whichever occurs later. \n3,300\n2. Repaired per Revision 9, 10, or 11 of Service Bulletin (cracks in structure).\t\nX-ray of E-N window post; and close visual of external strap.\t\n1,650 after effective date of this AD, or prior to accumulating 16,650 after repair, whichever occurs later. \n3,300 \n3. Modified per Revision 9, 10, or 11 of Service Bulletin (no cracks in structure).\nX-ray of E-N window post; and close visual of external strap.\n3,300 after effective date of this AD, or 24,000 after strap installation, whichever occurs later. \n6,600 \n\n\n\t\t\t\t\t TABLE 6 \n\n\t\t\tModel 737 E-N Window Post Inspection\n\t\t (Applicable Boeing Service Bulletin 737-53-1023 \n\n\nAirplane\nCondition\nInspection Required\nin accordance with\nRevision 9, 10, or 11of Service Bulletin\nInitial\nInspection\nnot to exceed\n(flight cycles)\nRepeat Inspection \nInterval not to exceed (flight cycles) \n1. Service\tBulletin not accomplished; or repaired or modified per Original Issue or Revision 1, 2, 3, 4, 5, 6, 7, or 8 of Service Bulletin. \nX-ray of E-N window post.\n2,750 after effective date of this AD, or prior to the accumulation of 12,750, whichever occurs later. \n5,500\n2. Repaired per Revision 9, 10, or 11 of Service Bulletin (cracks in structure).\t\nX-ray of E-N window post; and close visual of external strap.\t\n2,750 after effective date of this AD, or prior to accumulating 17,750 after repair, whichever occurs later. \n5,500\n3. Modified per Revision 9, 10, or 11 of Service Bulletin (no cracks in structure).\nX-ray of E-N window post; and close visual of external strap.\n5,500 after effective date of this AD, or 24,000 after strap installation, whichever occurs later. \n11,000\n\n\t(c)\tReinspect the affected areas for cracks at intervalsnot to exceed those specified in the "Repeat Inspection Interval" column of the Tables of paragraphs (a) and (b) of this AD.\n \n\t(d)\tCracks and short edge margins must be repaired, prior to further flight, in accordance with the "Accomplishment Instructions" of the applicable service bulletin specified in paragraph (d)(1), (d)(2), or (d)(3) of this AD. After such repair, inspections must continue in accordance with the Tables of paragraphs (a) and (b) of this AD. \n\n\t\t(1)\tFor Boeing Model 707/720 series airplanes: Boeing Service Bulletin 2983, Revision 5, dated January 31, 1991; or Revision 6, dated November 12, 1992. \n\n\t\t(2)\tFor Boeing Model 727 series airplanes: Boeing Service Bulletin 727-53- 0086, Revision 11, dated August 8, 1991. \n\n\t\t(3)\tFor Boeing Model 737 series airplanes: Boeing Service Bulletin 737-53- 1023, Revision 11, dated May 16, 1991. \n\n\t(e)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safetymay 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(f)\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(g)\tThe repairs shall be done in accordance with Boeing Service Bulletin 2983, Revision 5, dated January 31, 1991; Boeing Service Bulletin 2983, Revision 6, dated November 12, 1992; Boeing Service Bulletin 727-53-0086, Revision 11, dated August 8, 1991; and Boeing Service Bulletin 737-53-1023, Revision 11, dated May 16, 1991; as applicable. 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. 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(h)\tThis amendment becomes effective on May 5, 1993.