John Stapp

John Paul Stapp, M.D., Ph.D., Colonel, USAF (Ret.) (11 July 1910 - 13 November 1999) was a pioneer in studying the effects of deceleration on humans.

Dr. John Paul Stapp was born in Bahia, Brazil, the son of Reverend and Mrs. Charles F. Stapp.

His preliminary education was obtained at the Brownwood High School, Brownwood, Texas, and San Marcos Academy, San Marcos, Texas. Dr. Stapp received his bachelor's degree in 1931 from Baylor University, Waco, Texas; his master of art degree from Baylor in 1932; his doctorate in Biophysics from the University of Texas, Austin, Texas in 1940; and his medical degree from the University of Minnesota, Minneapolis, Minnesota, in 1944. He interned for one year at St. Mary's Hospital, Duluth, Minnesota. Stapp also received an honorary Doctor of Science degree from Baylor University.

Dr. Stapp entered the United States Air Force on 5 October 1944. On 10 August 1946, he was transferred to the Aero Medical Laboratory as project officer and medical consultant in the Bio-Physics Branch. His first assignment as a project officer included a series of flights testing various oxygen systems in unpressurized aircraft at 40,000 feet (12.2 km). He was assigned to the deceleration project in March 1947.

As far back as 1945, service personnel realized the need for a comprehensive and controlled series of studies leading to fundamental concepts that could be applied to better safeguard occupants of crashing airplanes. 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 whereby airplane crashes might be simulated, and to study the strength factors of seats and harnesses, and human tolerance to the acceleration encountered in simulated airplane crashes.

The crash survival research program was originally slated to be conducted near the Aero Medical Laboratory, but Muroc (now Edwards Air Force Base) was chosen because of the existence there of a 2000 foot (610 m) track, built originally for V-2 rocket research. That particular program had been completed and was taken over for the deceleration research program to save building a new track.

Designed to Aero Medical Laboratory specifications and fabricated by Northrop Aircraft of Hawthorne, California, equipment was maintained and operated on service contract by the Northrop Company.

The "human decelerator" consisted basically of a 1500 pound (680 kg) carriage mounted on a 2000 foot (610 m) standard gauge railroad track supported on a heavy concrete bed, and a 45 foot (14 m) mechanical braking system believed to be one of the most powerful ever constructed. Four slippers secured the carriage to the rails while permitting it to slide freely. At the rear of the carriage, 1000 lbf (4 kN) rockets provided the propelling force. Braking was accomplished by 45 sets of brakes, each consisting of two clasping pairs of brake surfaces installed on the road bed between the rails. These brake pairs clasped the 11 foot (3.4 m) long braking plates beneath the carriage chassis to apply the desired slowdown or deceleration. By varying the number and pattern of brake sets used and the number of carriage-propelling rockets, it was possible to control the deceleration.

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 of the early runs was in the developmental stage, and it was not until August 1948 that it was adequate enough to begin recording. By August 1948, 16 human runs had been made, all in the backward facing position. Forward facing runs were started in August 1949. Most of the earlier tests were run to compare the standard Air Force harnesses with a series of modified harnesses, to determine which type gave the best protection to the pilot.

By 8 June 1951, a total of 74 human runs had been made on the decelerator, 19 with the subjects in the backward position, and 55 in the forward position. Dr. Stapp, one of the most frequent volunteers on the runs, sustained a fracture of his right wrist during the runs on two separate occasions.

Dr. Stapp's findings on the decelerator have been applied to practical use. For instance, the backward-facing seat concept, which was known previously, was given great impetus by the officer's crash research program, which proved beyond a doubt that this position was the safest for airplane passengers and required little harness support, and that a human can withstand much greater acceleration than in the forward position. As a result, all of the Air Force Military Air Transport Ships (MATS) were equipped with this type seat. Commercial airlines were made aware of these findings. The British Royal Air Force also installed it on many of their military transports.

As a result of Dr. Stapp's findings, the acceleration requirement for fighter seats was increased considerably up to 32 gees (310 m/s²) since his work showed that a pilot could walk away from crashes when properly protected by harnesses, and if the seat does not break loose.

The "side saddle" or sideways-facing harness was developed also by Dr. Stapp. The new triangular shaped harness gave vastly increased protection to fully-equipped paratroopers sitting side-by-side in Air Force airplanes. It was made of nylon mesh webbing, fit snugly over the shoulder facing the forward part of the airplane, and protected the wearer from the force of crash impacts, takeoffs and landing bumps. It withstood a crash force of approximately 8000 pounds force (36 kN) at 32 g (310 m/s²) and was developed to replace the old-fashioned lap belts which gave inadequate protection to their wearers.

By riding the decelerator sled himself, Dr. Stapp demonstrated that a human can withstand at least 45 g (440 m/s²) in the forward position, with adequate harness. This is the highest known acceleration voluntarily encountered by a human. Dr. Stapp believed that the tolerance of humans to acceleration had not yet been reached in tests, and is, in fact, much greater than ordinarily thought possible.

Also developed by Dr. Stapp as an added safety measure was an improved version of the currently used shoulder strap and lap belt. The new high-strength harness withstood 45.4 g (445 m/s²), compared to the 17 g (167 m/s²), which was the limit that could be tolerated with the old combination. Basically, the new pilot harness added an inverted "V" strap crossing the pilot's thighs added to the standard lap belt and shoulder straps. The leg and shoulder straps and the lap belt all fastened together at one point, and pressure was distributed evenly over the stronger body surfaces, hips, thighs and shoulders, rather than on the solar plexus, as was the case with the old harness.

Dr. Stapp also participated in wind-blast experiments, in which he flew in jet aircraft at high speeds to determine whether or not it was safe for a pilot to remain with his airplane if the canopy should accidentally blow off. Dr. Stapp stayed with his aircraft at a speed of 570 miles per hour (917 km/h), with the canopy removed, and suffered no injurious effects from the wind blasts. He also supervised research programs in the fields of human factors in escape from aircraft and human tolerance to abrupt acceleration and deceleration.

Stapp is credited with creating Stapp's Law (or Stapp's Ironical Paradox) during his work on the project.

In the years before his death, Dr. Stapp was president of the New Mexico Research Institute, headquartered in Alamogordo, New Mexico, as well as chairman of the annual Stapp Car Crash Conference. This event meets to study car crashes and determine ways to make cars safer. In addition, Dr. Stapp was honorary chairman of the Stapp Foundation, which is underwritten by General Motors and provides scholarships for automotive engineering students.

Dr. Stapp died peacefully at his home in Alamagordo, New Mexico, at the age of 89.

See also: Murphy's law Stapp's Law

References

Based in part on the public domain article http://www.edwards.af.mil/history/docs_html/people/stapp_biography.html, published by the Air Force Flight Test Center Public Affairs Office, Edwards Air Force Base, which is based in turn upon the public domain article http://www.wpafb.af.mil/museum/afp/afp1199.htm, published by The Air Force Museum, Wright Patterson Air Force Base.

External links

• Stapp Car Crash Conference (http://www.stapp.org)
• Air Force Museum web site (http://www.edwards.af.mil/history/docs_html/people/stapp_biography.html)
• National Aviation Hall of Fame web site (http://www.nationalaviation.org/website/index.asp?webpageid=%7BF3401AC2-408C-42A7-AD0F-CDDC7942F110%7D&eID=394)
• Encyclopedia Austronautica (http://www.astronautix.com/astros/stapp.htm)