John Stapp

John Paul Stapp (July 11, 1910 – November 13, 1999) was an American career U.S. Air Force officer, flight surgeon, physician, biophysicist, and pioneer in studying the effects of acceleration forces on humans.

He was a colleague and contemporary of Chuck Yeager, and became known as "the fastest man on earth".

His work on Project Manhigh pioneered many developments for the US space program.

Born in Salvador de Bahia, Brazil, Stapp was the eldest of four sons of Reverend Charles Franklin Stapp and Mrs. Mary Louise Shannon, Baptist missionaries.

He studied in Texas at Brownwood High School in Brownwood and San Marcos Baptist Academy in San Marcos.

In 1931, Stapp received a bachelor's degree from Baylor University in Waco, an MA from Baylor in 1932, a PhD in Biophysics from the University of Texas at Austin in 1940, and an MD from the University of Minnesota, Twin Cities, in 1944.

He interned for one year at St. Mary's Hospital in Duluth, Minnesota.

Stapp was later awarded an honorary Doctor of Science from Baylor University.

Stapp entered the U.S. Army Air Forces on 5 October 1944 as a physician and qualified as a flight surgeon.

As early as 1945, service personnel realized the need for a comprehensive and controlled series of studies into the effects of deceleration on the human body.

This led to fundamental concepts that could be applied to better safeguard aircraft occupants during a crash.

The initial phase of the program, as set up by the Aero Medical Laboratory of the Wright Air Development Center, was to develop equipment and instrumentation.

This was so aircraft crashes might be simulated, and to study the strength factors of seats and harnesses.

Human tolerance to the deceleration encountered in simulated aircraft crashes could also be simulated.

On 10 August 1946, he was assigned to the Aero Medical Laboratory at Wright Field as a project officer and medical consultant in the Biophysics Branch and transferred to the U.S. Air Force when it became an independent service in September 1947.

His first assignment included a series of flights testing various oxygen systems in unpressurized aircraft at 40,000 ft (12.2 km).

One of the major problems with high-altitude flight was the danger of "the bends" or decompression sickness.

Stapp's work resolved that problem as well as many others, which allowed the next generation of high-altitude aircraft and the HALO insertion techniques.

He was assigned to the deceleration project in March 1947.

The first run on the rocket sled took place on 30 April 1947 with ballast.

The sled ran off the tracks.

The first human run took place the following December.

Instrumentation on all the early runs was in the developmental stage, and it was not until August 1948 that it was adequate to begin recording.

By August 1948, sixteen human runs had completed, all in the backward-facing position.

Forward-facing runs started in August 1949.

Most of the earlier tests ran to compare the standard Air Force harnesses with a series of modified harnesses.

This was to determine which type gave the best protection to the pilot.

By June 8, 1951, 74 human runs had been made on the decelerator, 19 with the subjects in the backward position, and 55 in the forward position.

Stapp, one of the most frequent volunteers on the runs, sustained a fracture of his right wrist during the runs on two separate occasions, also broke ribs, lost fillings from his teeth and developed bleeding into his retinas that caused temporary vision loss; in one run he survived forces up to 38 g.

Stapp's research on the decelerator had profound implications for both civilian and military aviation.

For instance, the backward-facing seat concept, which was known before, was given great impetus by the crash research program.

It proved beyond a doubt that this position was the safest for aircraft passengers and required little harness support, and that a human can withstand much greater deceleration than in the forward position.

As a result, many Military Air Transport Service (MATS) aircraft in USAF and carrier on-board delivery aircraft in USN were equipped or retrofitted with this type of seat.

Commercial airlines were made aware of these findings, but still use forward-facing seats.

The British Royal Air Force also installed it on many of their military transport aircraft.

As a result of Stapp's findings, the acceleration requirement for fighter seats was increased considerably up to 32 g (310 m/s²).

His work showed that a pilot could walk away from crashes when properly protected by harnesses if the seat does not break loose.

The "side saddle" or sideways-facing harness was also developed by Stapp.

In 1967, the Air Force loaned Stapp to the National Highway Traffic Safety Administration to conduct auto-safety research.

He retired from the U.S. Air Force in 1970 with the rank of Colonel.