82-10-04 MCDONNELL DOUGLAS: Amendment 39-4378. Applies to McDonnell Douglas DC-9, series 30, 50, 80 and C-9B airplanes certificated in all categories, with factory serial numbers listed in Service Bulletin A27-234. Compliance required within 90 days unless already accomplished. \n\n\tTo prevent loss of ability to trim the aircraft by use of the primary longitudinal trim system, accomplish the following: \n\n\tA.\tDetermine serial number of horizontal stabilizer alternate longitudinal trim motor P/N D1775 by visual examination of motor or from aircraft maintenance records. \n\n\tB.\tReplace trim motor if serial number is listed in table of item #2 in Service Bulletin A27-234. \n\n\tNOTE: Service Bulletin A27-234 contains recommended procedures for gaining access to the horizontal stabilizer alternate longitudinal trim motor, and for checkout of the trim system subsequent to replacement of the motor. \n\n\tC.\tAlternative means of compliance which provide an equivalent level of safety maybe used when approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region. \n\n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). \n\n\tAll persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director, Publications and Training, C1-750 (54-60). \n\n\tThese documents also may be examined at FAA Northwest Mountain Region, 17900 Pacific Highway South, C-68966, Seattle, Washington 98168; or Los Angeles Area Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California 90808. \n\n\tThis Amendment becomes effective May 18, 1982.