81-04-51 R1 MCDONNELL DOUGLAS: Amendment 39-4107 as amended by amendment 39-4281. Applies to McDonnell Douglas Model DC-9-80 series airplanes, fuselage numbers 924 through 1017 inclusive, certificated in all categories. Compliance required as noted in the body of this AD, unless already accomplished. To prevent unscheduled deployment of the thrust reversers during approach prior to touchdown, accomplish the following: \n\n\tA.\tEffective immediately after the effective date of this AD, the flight crew shall disengage the autothrottle during approach prior to reaching 50 feet AGL. \n\n\tB.\tWithin 48 hours calendar time after receipt of this AD, unless already accomplished: \n\n\t\t1.\tPlacard each aircraft in clear view of each pilot with the following wording: "Disengage ATS on approach before reaching 50 feet AGL." \n\n\t\t2.\tThe FAA-approved Airplane Flight Manual shall be revised to add the following in the limitations section: \n\n\t\t\tAUTOTHROTTLES: The autothrottles must be disengaged during approach before reaching 50 feet AGL. \n\n\tC.\tAlternate means of compliance or other actions which provide an equivalent level of safety may be used when approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Region. \n\n\tD.\tIncorporation of the modifications in accordance with Part 2, Accomplishment Instructions, of McDonnell Douglas DC-9 Super 80 Service Bulletin 78-47 dated August 4, 1981, or later revisions approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region, constitutes terminating action. Following such modification, both the placard and the Airplane Flight Manual limitation required by A. and B. above may be removed. \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). This document also may be examined at FAA Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington 98108; or the Los Angeles Area Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California 90808. \n\n\tAmendment 39-4107 became effective May 14, 1981, to all persons, except to whom it was made immediately effective by telegram dated February 9, 1981. \n\n\tThis amendment 39-4281 becomes effective December 28, 1981.