78-23-06 MCDONNELL DOUGLAS: Amendment 39-3343. Applies to McDonnell Douglas DC-9-10, -20, -30, -40, -50 series airplanes, including the military versions, all serial numbers, certificated in all categories. \n\n\tCompliance is required within one year after the effective date of this AD. \n\n\tTo reduce the probability of an unnecessary rejected takeoff due to a false stall warning just after initiation of rotation, modify the stall warning system by extending the time delay to four seconds between nose gear lift-off and the initiation of stall warning, by accomplishing the following: \n\n\t(a)\tModify the stall warning circuitry in accordance with McDonnell Douglas DC-9 Service Bulletin 34-131 dated January 10, 1978. \n\n\tNOTE: Service Bulletin 34-131 dated January 10, 1978, is the only version of this service bulletin suitable for compliance with paragraph (a) of this AD. \n\n\t(b)\tEquivalent modifications, procedures, or revisions may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(c)\tSpecial flight permits may be issued in accordance with FAR's 21.197 and 21.199 to operate airplanes to a base for accomplishment of the modification required by this AD. \n\n\tThis amendment becomes effective December 11, 1978.