"On This Day" In Engineering History

On this day in engineering history, the U.S. Air Force performed the first test in Project Whoosh, a series of experiments that were designed to evaluate escape from an aircraft traveling at Mach 2. In the years after World War II, advances in aerospace technology produced jet planes that could travel at speeds greater than 500 mph. Pilots who flew at such high velocities were often unable to escape from their aircraft, however. Indeed, from 1949 to 1956, only 20% of pilots who ejected did so without harm. As the U.S. military competed in both the Cold War and the Space Race, aerospace biology and the design of better ejection seats became important fields of study.

Missiles and Sleds

In the early 1950s, the U.S. Air Force established an Aeromedical Field Laboratory (AMFL) at Holloman Air Force Base (AFB) near Alamogordo, New Mexico. Although Holloman AFB was involved mainly in missile research, including work with captured V-2 rockets, it also featured a 3,550-foot rail track for deceleration experiments. Led by Lt. Colonel John Paul Strap, the Alamogordo AMFL recruited human test subjects who volunteered to ride rocket-propelled sleds on missions that subjected participants to breaking forces around 35 g's. For the most dangerous experiments, however, animal test subjects were used.

Sonic Wind

Armed with higher-speed sleds called Sonic Wind 1 and Sonic Wind 2, the Air Force conducted a series of experiments to study survival limits for deceleration, windblast, tumbling, and other factors. Many of these experiments involved chimpanzees, most of which were seriously injured or killed while testing helmets, head rests, and windshields. For example, a monkey about Sonic Wind 1, a decompression sled built by Northrop Aircraft, traveled at 400 mph before coming to an abrupt stop that caused severe head trauma and death. A chimpanzee aboard Sonic Wind 2 met a similar fate when a helmet designed by Protection Inc. failed before Mach 1.7 was even achieved.

Project Whoosh

Project Whoosh took supersonic travel off the track and into the skies. According to the NASA History web site, this phase of Air Force research ejected chimpanzees from Cherokee missiles taken aloft by B-29 bombers. Once the aircraft reached an altitude of approximately 6 miles, the Cherokee was dropped and descended by parachute to about 5 miles, when a solid-fueled rocket motor accelerated the missile to supersonic speeds. The chimp was then ejected from an open seat.

Beginning with the first test of Project Whoosh on July 8, 1955, all of the chimpanzees died because of equipment failures with either the parachute system or ejection seat. "Nevertheless," the NASA web site notes, "this project was not a total loss" since "the failures were instructive". Eventually, "the work performed on Whoosh led directly to further ejection experiments at the Supersonic Military Air Research Track, Hurricane Mesa, Utah."

Resources:

http://history.nasa.gov/afspbio/part4-4.htm

http://www.releasechimps.org/harm-suffering/research-history/air-space/

http://books.google.com/books?id=xSdHVIpsrKkC&pg=PA107&lpg=PA107&dq=project+whoosh+&source=web&ots=bMHjUWt4u0&sig=H7gtet-_WdC_aBGCT6MuJ-hGZeE&hl=en&sa=X&oi=book_result&resnum=10&ct=result

http://historytogo.utah.gov/utah_chapters/utah_today/hurricanesamgavepilotsasafetyedge.html

http://www.designation-systems.net/dusrm/app4/cherokee.html