71-08-01 MCDONNELL DOUGLAS: Amdt. 39-1187. Applies to DC-9 series airplanes incorporating automatically deployed emergency evacuation slides in the tailcone area. \n\n\tCompliance required within the next 300 hours' time in service after the effective date of this AD, unless already accomplished. \n\n\tTo prevent failure of the aft evacuation slide automatic deployment system, inspect the two attaching rivets for the evacuation slide lanyard attach plate and verify that the Douglas P/N 5924584-3 plate is attached to the tail cone ring with MS 20470AD4 (1/8 inch diameter) rivets as specified in Douglas Aircraft Company, All Operators Letter (AOL) 9-527 dated November 19, 1970 and/or Douglas Aircraft Division DC-9 Service Bulletin NO. 25-118 dated August 27, 1968, or later FAA-approved revisions. If rivets of less than 1/8 inch diameter are installed, they must be replaced with MS 20470AD4 (1/8 inch diameter) rivets or No. 8 or No. 10 corrosion resistant steel screws and locknuts, oran equivalent method of attachment as approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective April 20, 1971.