Seat belts, airbags even ejector seats in planes, we take these types of safety
devices for granted and they have saved thousands of lives.
Virtually anything that carries people these days from cars to planes to
spacecraft have been tested using sophisticated test dummies but that
wasn't always the case. In the early days of jet aircraft and at beginning of a
space race some truly brave people risked life and limb in some amazing
experiments. In the nineteen fifties with a new generation of high-speed jets
taking to the skies, escaping from a damaged plane, high-speed banking and
acceleration, the risk of high-altitude flying and even crash landing all became
great unknowns. In the past animals or even deceased human bodies, cadavers had
been used in tests. The problem with this kind of test subject is if they couldn't
operate equipment during the test or report back as to what had happened to
them and what the effects were not only on their physical condition but also
just as importantly on how it affected their mental capabilities. However one
man, Captain John Stapp, a medical doctor and qualified flight surgeon for the
USAF was willing to push the boundaries of what was thought possible not what
performing tests on animals and dummies but on himself. His first assignment was
with the Aero medical lab and was into the effects of high altitude flight. In
1946 Stapp was flown in the rear of a heavily modified B-17 bomber into the
stratosphere to a height of around 45,000 feet to see how it would be
possible for the crew to survive the cold and lack of oxygen. These tests
would be crucial for the future of aviation. One of the mysteries of
high-altitude flying was how they could stop the bends or high altitude sickness
from occurring this is the same condition that affected deep-sea divers
when they ascended back to the surface too quickly. This happened in the very
low pressure atmosphere at high altitudes or in sudden decompression events.
Nitrogen which is normally dissolved in the blood comes out of solution and
forms gas bubbles causing anything from pain and rashes to confusion
unconsciousness or even death in a very short space of time. Stapp spent 65 hours
in the back of the B-17 performing different tests on himself, in the end he
discovered but if he breathed pure oxygen for 30 minutes prior to the
flight, the condition could be eradicated. This is because he was effectively
flushing nitrogen out of his body with pure oxygen. This was a major
breakthrough and his next task was to lead the aero medical labs most
important research project into the effects of deceleration on the human
body and it would lead him and his crew to performing some truly I watering
experiments. One of the reasons why the USAF wanted to explore the effects of
deceleration was at the time it was thought that 18 G's was the limit that
any human could survive. Because 18 G's was the upper limit things like
harnesses and seats were only rated and built to handle that amount. However in
numerous occasions on aircraft carriers pilots had survived high speed crashes
and higher forces that should have killed them and yet they walked away and
then others had proved fatal at very low speed because their harnesses or the
planes structure had failed. There was also the upcoming problem of supersonic
jet flight and the need to eject at supersonic speeds, no one knew if a crew
could survive such an ejection. The experiments would take place at a 609
meter long track at the Moroc base later renamed Edwards Air Force Base, this had
previously been used to test captured German V1 flying bombs. A rocket-powered
sled nicknamed the Gee-whiz with a wooden windshield protect the occupant would be
propelled down the track and at the other end a set of hydraulic brakes in
the track would slow it from 240 kilometers per hour
to half that in 1/5 of a second and this would simulate the g-forces of
a plane crash. The sled was meant to use an 84 kilogram dummy named Oscar Eightball
but Stapp had other ideas and told the Northrop manager that he would be
the test subject. Before staff did any tests on himself the system had to be
tested thoroughly as any mistake could prove fatal. During one of the setup
tests they sent Oscar 8-ball down the track with just a lap belt, when the sled
hit the brakes they locked up instantly producing 30 G's, the belt broke and
Oscar went through a 2.5cm thick wooden windshield as if
it were paper and ended up some 216 metres past the end of a track, clearly
better harnesses were going to be required. After 35 test runs and eight
months Stapp thought he and his team had enough experience to start man tests the
first one was with Stapp on the g-wiz facing backwards using just one rocket
this reached a 145 kilometers an hour and 10 G. The next day
he added two more rockets and reached 320 kilometers
with no ill effects. Further tests with increasing speeds and differing
deceleration rates followed and by August 1948 staff had done sixteen tests
and survived up to 35 G. Although Stapp that found the earlier tests easy the later
ones were much more stressful with him suffering concussions, a broken wrist and
cracked ribs. The most disturbing effect Stapp noted was the White out when
facing backwards in the sled. This was because the blood was leaving his eyes
and pooling in the back of his head under the high g-forces. When he changed to
face forwards he experienced red outs this time the pressure of a blood being
forced forwards was bursting the capillaries in his eyes. This remained a
constant issue throughout the later tests proving that the eyes were the
most vulnerable parts although to be totally accurate it was the blood or
lack of which was causing the problem. Although
Stapp was reprimanded for exceeding the 18g limit the data he collected was so
useful information he was told to use chimpanzees instead. He had already proved the
inefficiency of many harnesses fitted to aircraft and that rear-facing passengers
in planes were much more likely to survive a crash and forward-facing ones.
The Air Force immediately changed the harnesses in its planes and reconfigured
its troop transport planes for rear-facing passengers but there was
still be issue of supersonic ejection and that was beyond the limits of the
gee-whiz. Although Stapp did some tests in a special open cockpit f-89 what became
clear was that a new test vehicle was required. In 1953 a new track was built
with a new rocket-powered sled called the Sonic Wind No.1, this was capable of
reaching 1,200 kilometers an hour and was standing a 150 G.
Instead of using breaks the sled would run through a water trough and use
scoops to catch a redirect the water to create the braking. In November 1953
Stapp was fired down the track that's 677 km/h when the sled hit the water it
generated 22 G dropping to 15 G for 0.6 seconds twice as long as
the Gee-whiz. Stapp said afterwards that he felt fine and that he hoped to do it
again later that day, it actually took five months to do the next test but this
time it would be forward-facing with no windshield just a helmet and visor like
a pilot would be wearing and the sled speed would be wound up to the max. This
would be steps 29th and final test. The sled would also be followed by a T-33
jet fighter to observe and take photos of a test from above. As the run started
the sled accelerated to 1017 km/h by six rockets making Stapp the fastest man on
earth, faster than a bullet and exposing him to a wind pressure of nearly two
tons and an acceleration force of 20 G. Joe
Kittinger who piloted the chase plane said the sled went past him as if he was
standing still and he had the throttle wide open doing 560 km/h.
Kittinger said that when the sled hit
the water break it looked like it hit a concrete wall so quick was the
deceleration he couldn't believe anyone would survive it but survive it stapp
did, he endured 46.2 G's for 1.1 seconds the equivalent of a
pilot ejecting at Mac 1.6 at 40,000 feet. The jolt he received was greater than
that of a car driver hitting a brick wall at a 195 km/h.
When the medics got to the sled Stapp was conscious but when
they saw his eyes they were completely filled with blood. He was taken to
hospital and feared but he might have gone too far this time and blinded
himself but within 24 hours his sight had returned to almost normal.
Stapp was preparing for an even faster test of 1,600 kilometers , thats 1000mph
but the top brass thought he was pushing his luck too far and
didn't allow him to continue, which was just as well because during an unmanned
80g test the sled came off the rails and was severely damaged, if it had been on
board at the time he would have been killed.
Stapp became a great advocate for better safety in cars. In 1966 and because of
his work it became law to have seat belts fitted in cars in the US, although others
had done tests - Stapp had taken it to the limit and then some. Soon dummies
would take over but Stapp would continue his work with the aviation and
automobile industry up until his death in 1999 at the age of 89. If you've ever
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