89-07-02 McDONNELL DOUGLAS: Amendment 39-6158. \n\n\tApplicability: McDonnell Douglas Model DC-8 series airplanes, equipped with rudder drive torque tube crank assembly, P/N 5647102-1 or -501, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent the loss of directional control of the airplane in critical flight regimes due to fatigue failure of the rudder drive torque tube crank assembly, accomplish the following: \n\n\tA.\tWithin the next 1,000 hours time-in-service after the effective date of this AD, unless already accomplished within the last 2,600 hours time-in-service, conduct an eddy current inspection of the rudder drive torque tube crank assembly, in accordance with the accomplishment instructions in McDonnell Douglas DC-8 Service Bulletin 27-268, dated February 9, 1988, or equivalent inspection technique approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tB.\tIf no cracks are found, repeat the inspection in accordance with paragraph A. of this AD at intervals not to exceed 3,600 hours time-in-service. \n\n\tC.\tIf cracks are found, accomplish one of the following: \n\n\t\t1.\tReplace the cracked rudder drive crank assembly (P/N 5647102-1 or -501) with P/N 5647102-501, in accordance with McDonnell Douglas DC-8 Service Bulletin 27-268, dated February 9, 1988, and repeat inspections in accordance with paragraph B. of this AD; or \n\n\t\t2.\tReplace the rudder drive crank assembly with P/N 5647102-503 in accordance with McDonnell Douglas DC-8 Service Bulletin 27-268, dated February 9, 1988. \n\n\tD.\tReplacement of the rudder drive crank assembly with P/N 5647102-503, in accordance with McDonnell Douglas DC-8 Service Bulletin 27-268, dated February 9, 1988, constitutes terminating action for the repetitive inspections required by this AD. \n\n\tE.\tAlternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tF.\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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publications, C1-L00 (54-60). These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or at 3229 East Spring Street, Long Beach, California. \n\n\tThis amendment (39-6158, AD 89-07-02) becomes effective April 26, 1989.