John Stapp (1910-1999), US aviation researcher, on a the Gee Whizz rocket sled at Edwards Air Force Base, California, USA. Stapp pioneered the study of the effects of deceleration on humans. He gained a doctorate in biophysics and a degree in medicine before joining the US Air Force in 1944. From 1946 he worked on the deceleration project that was studying how pilots could survive crashes. A rocket sled was used to simulate the deceleration experienced during an aeroplane crash. The system began operating in 1947 and by August 1948, several runs involving humans had been made. Stapp was one of the most frequent volunteers. Stapp's work led to the design of improved safety harnesses for aircraft pilots.