Army physician who studied the effects of acceleration and deceleration g-forces on humans. As a result of the findings of his experiments the British Royal Air Force began installing backward-facing seats because he found they were safer.
As a member of the Air Force Aero Med Lab, his reach looked into the effect of high altitude flight on passengers - conducted in the days before pressurized cabins and temperature control.
To test what would happen if a pilot were ejected during supersonic flight, he built a rocket-powered sled on rails in New Mexico, launched himself up to 420 mph, and decelerated to a stop within seconds.
He was born in was born in Bahia, Brazil, the son of a reverend.
He helped along Chuck Yeager's breakthrough supersonic flights, and he, not Yeager, became known as "the fastest man on Earth."