91-09-07 BOEING: Amendment 39-6982. Docket No. 90-NM-218-AD. Supersedes AD 83- 03-01 R1. \n\n\tApplicability: Model 727 series airplanes, listed in Boeing Service Bulletin 727-53- 0153, Revision 5, dated December 14, 1989, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo ensure the structural integrity of the forward entry doorway forward frame, accomplish the following: \n\n\tA.\tVisually inspect the forward entry doorway frame for cracks in accordance with Boeing Service Bulletin 727-53-0153, dated February 1, 1980, or Revisions 1 through 5, at the earlier of the times indicated in subparagraphs A.1. or A.2. of this AD, and repeat the inspection at intervals not to exceed 3,700 landings: \n\n\t\t1.\tWithin the next 1,850 landings after March 11, 1983 (the effective date of Amendment 39-4561), or prior to accumulating a total of 25,000 landings, whichever occurs later; or \n\n\t\t2.\tWithin the next 1,850 landings after May 16, 1986, (the effective date of Amendment 39-5283), or prior to accumulating a total of 15,000 landings, whichever occurs later. \n\n\tB.\tFor airplanes modified in accordance with Boeing Service Bulletin 727-53-0153, dated February 1, 1980, through Revision 4, dated November 8, 1985, conduct the inspections described in paragraph A. of this AD prior to the accumulation of 10,000 landings after the modification or within the next 3,700 landings after the effective date of this AD, whichever occurs later. Repeat the inspection at intervals not to exceed 3,700 landings. \n\n\tC.\tCracked structure must be repaired prior to further flight, in accordance with Boeing Service Bulletin 727-53-0153, Revision 5, dated December 14, 1989, or earlier FAA- approved revisions. Repair in accordance with Revision 2 through 5 of the service bulletin constitutes terminating action for the requirements of this AD. \n\n\tD.\tModification in accordance with Boeing Service Bulletin 727-53-0153, Revision 5, dated December 14, 1989, constitutes terminating action for the requirements of this AD. \n\n\tE.\tFor the purpose of complying with this AD, subject to acceptance by the assigned FAA Principal Maintenance Inspector, the number of landings may be determined by dividing each airplane's number of hours time-in-service by the operator's fleet average time from takeoff to landing for the airplane type. \n\n\tF.\tAn alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may concur or comment and then send it to the Manager, Seattle ACO.\n \n\tG.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. \n\n\tAirworthiness Directive 91-09-07 supersedes AD 83-03-01 R1 (Amendment 39-5283), which revised AD 83-03-01 (Amendment 39-4561). \n\n\tThis amendment (39-6982, AD 91-09-07) becomes effective on May 28, 1991.