May 14, 1953: The Braking System of the Experimental High Speed Track Successfully Recovered a 2500 Pound Test Sled

  • Published
  • Air Force Flight Test Center

The braking system of the 10,000 foot Experimental High Speed Track successfully recovered a 2500 pound. Test sled from a velocity of Mach 1.03 (816 miles per hour), thereby increasing the capability of the new test facility to that level. The track was used for testing aircraft ejection seats, parachute development, and the first Human Factors testing, Project Windblast.

The research project that Colonel Stapp personally brought to Holloman when he came to assume command of the Center's Aeromedical Field Laboratory in April 1953-Biophysics of Abrupt Deceleration-was specifically oriented toward the study of high-speed escape from aircraft. The escape problem remained one of the most important research topics of Project 7850, Biodynamics of Human Factors in Aviation, that was drawn up in 1954 to supplement and in large measure to supersede the former project. Research on this same theme has been reoriented but by no means eliminated since March 1958, when Project 7850 was rewritten as Biodynamics of Space Flight. And it was a series of experiments directly related to escape physiology, Colonel Stapp's own rocket-sled rides on the Holloman track, that first brought nationwide attention to the Holloman aeromedical organization.  The high-speed escape problem was one of imposing magnitude. A pilot bailing out at transonic or supersonic speed had to face first the ejection force required to get him out of his plane, then the sudden onslaught of windblast and wind-drag deceleration, likely to be followed by dangerous tumbling and spinning. Any one of these forces taken separately was a potential cause of injury or death, not to mention the anxiety on the part of aircraft pilots who did not know if they would survive or not in case of ejection. For, at the time research on this problem at Holloman began, the escape systems available were either admittedly inadequate or of unproven worth for aircraft having performance capabilities above mach one in speed and 45,000 feet in altitude. Since aircraft with this range of performance were already in existence, and were destined to assume ever greater importance in the Air Force inventory, there was a glaring need for reliable data on human tolerance to all the forces that could be encountered in escape at the indicated speeds and elevations. The fact that such information was not already available was another case of the lag, often deplored by aeromedical scientists, between aircraft design and human factors research.