87-21-04 McDONNELL DOUGLAS: Amendment 39-5737. Applies to McDonnell Douglas Model DC-10 and KC-10A series airplanes, certificated in any category. Compliance required as indicated, unless previously accomplished. \n\n\tTo prevent failure of the inboard slat drive arm due to fatigue, accomplish the following: \n\n\tA.\tPrior to the accumulation of 10,000 landings, or within 15 days after the effective date of this AD, whichever occurs later, unless previously accomplished within the last 90 days, and thereafter at intervals not to exceed 2,000 landings, inspect the inboard slat drive arm in accordance with the expanded magnetic particle, ultrasonic, or eddy current inspection (Option 2) procedures in the Accomplishment Instructions in McDonnell Douglas Service Bulletin A27-203, Revision 1, dated July 9, 1987, or later FAA-approved revision. \n\n\t\t1.\tIf crack(s) are found that are beyond the reworkable limits defined by McDonnell Douglas Service Bulletin A27-203, Revision 1, dated July9, 1987, or later FAA-approved revision, before further flight, replace the cracked arm in accordance with that Service Bulletin. \n\n\t\t2.\tIf crack(s) are found that are within the reworkable limits defined by McDonnell Douglas Service Bulletin A27-203, Revision 1, dated July 9, 1987, or later FAA-approved revision, before further flight, rework or replace the arm in accordance with the Accomplishment Instructions in that Service Bulletin. \n\n\tB.\tAlternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tC.\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 information from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publication, C1-L00 (54-60). This information may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California. \n\n\tThis Amendment becomes effective October 30, 1987.