Stealth Pilot wrote:
On Wed, 23 May 2007 15:12:00 +0000 (UTC),
(Paul Tomblin) wrote:

In a previous article, wright1902glider said:
a few dragsters that I've sat in. Not much between your backside and
the world. I've been considering an pioneer-era plane that has a very
low seating position and I've often thought about how to prevent
injury from spinal compression. I've thought about EPS foam like the
kind used in helmets as a way to absorb some of the energy. I know
that paraglider pilots have some sort of protection built into their
harnesses, but I've never seen exactly what its made of. Anyone ever
do any testing in this area?
It doesn't matter what sort of foam you've got if you haven't got
distance. You've got to get from the speed you impact at to zero in the
distance your butt is above the ground at impact, and the only way to make
it safer is to make raise your butt to give you more distance and fill the
gap with something that will use the whole distance to decellerate.

soft foam padding actually adds to the damage by delaying the onset of
deceleration of your body.

I read of a vertical slide tester that was set up to thest just this
problem and calibrated with the dummy sitting on a block of white
polystyrene just to get it in position.
then the various seats were put in place and tested for crash
worthiness.
the testers were surprised that none of the seats performed as well as
the polystyrene block.

If you look at a corby starlet plan the pilot is sitting on a six inch
block of polystyrene for just this reason.

Stealth Pilot

I came to this conclusion 5 or 10 years ago & found some Urethane foam
that has more density & NO resilience than styrofoam & it's not
flammable either I have about 7" of room..Jerry