76-07-05 BOEING: Amendment 39-2569. Applies to all Boeing Model 727 series airplanes, certificated in all categories, which are equipped with Boeing P/N 65-18949-1 nose landing gear release mechanism torsion shafts not affected by AD 73-26-06. Compliance required as indicated. \n\tTo prevent failure of the nose landing gear release mechanism torsion shaft and a resulting possible gear-up landing, accomplish the following: \n\tA.\tWithin the next 750 landings after the effective date of this AD, unless accomplished within the last 750 landings, and thereafter at intervals not to exceed 1,500 landings for shafts inspected in accordance with the ultrasonic inspection procedures or 2,400 landings for shafts inspected in accordance with the magnetic particle inspection procedures, inspect the P/N 65- 18949-1 shafts, reworked and nonreworked, which have accumulated 8,000 or more total landings since reworked or new, respectively, on or after the effective date of this AD, per paragraph Bbelow until the shaft is replaced per paragraph C. \n\tB.\tInspect the torsion shaft bearing surface in accordance with the ultrasonic or magnetic particle inspection procedures specified in paragraph III of Boeing Service Bulletin No. 727-32-238, or later FAA approved revisions, or inspect in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Shafts found cracked must be replaced prior to further flight, per paragraph C or with either one of the following: \n\t\t1.\tA nonreworked P/N 65-18949-1 shaft which has accumulated less than 8,000 landings. (Upon accumulation of 8,000 landings the inspection requirements of paragraph A above apply); or \n\t\t2.\tAn uncracked shaft, P/N 65-18949-1, which has been reworked once in accordance with Boeing Service Bulletin No. 727-32-203, Revision 3, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. These shafts are subject to the inspection provisions of paragraph A upon accumulation of 8,000 landings after initial rework. Additional rework will not thereafter exempt the shaft from the inspection requirements. \n\tC.\tInstallation of a new improved shaft, P/N 65-86496-1, and associated parts in accordance with Boeing Service Bulletin Nos. 727-32-205, or 727-32-223, or later FAA approved revisions, or an equivalent installation approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, constitutes terminating action of this AD. \n\tD.\tFor the purpose of this AD, when conclusive records are not available to show the number of landings accumulated by a particular shaft, the number of landings may be computed by dividing the airplane time in service since the shaft was installed in the airplane by the operator's fleet average time per flight for his Model 727 airplanes. \n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made apart hereof pursuant to 5 U.S.C. 552(a)(1). \n\tAll persons affected by this directive, who have not already received these documents from the manufacturer, may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. The documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98124. The documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington.\n \n\tThis amendment becomes effective May 11, 1976.