Following an accident on 30 July 1966 in the attempted launch of a D-21 drone, two Lockheed M-21 Crickmore, Paul F. "Lockheed's Blackbirds: A-12, YF-12 and SR-71", Wings of Fame, Volume 8, AIRtime Publishing Inc., Westport, Connecticut, 1997, , page 90 crew members ejected at Mach 3.25 at an altitude of 80000 feet .