"Human deceleration tolerances beyond the limits imposed by voluntary experimental methods were studied by means of intensive case histories of 137 individuals who have survived extremely abrupt impacts in accidental, suicidal, and homicidal free-falls. Fall distances ranged up to 275' and calculated velocities up to 116 ft/sec (79 mph). Physical and biological data are presented on both sexes with an age range of 1 1/2 to 91 years, and with impacts occurring in all body axis orientations. A detailed analysis of factors found to affect survivability in free-fall impacts is made. These cases, out of some 12,000 free-falls collected in the past two years, demonstrate that humans have survived impact forces considerably greater than those previously believed tolerable."--Abstract.