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From: "Gary Casey" <glcasey@adelphia.net>
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Subject: glare shields
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<<Is energy absorption during a crash a major consideration when
designing glare-shields?  Or do we just depend on shoulder harnesses?>>

I think it is an important crashworthiness item and I have thought about it
some - but I'm not much of an expert.  Some thoughts I've had:

1.  Make the outer portion of the glare shield from aluminum wrapped to form
at least a 1 inch blunt end.  The aluminum should deflect and absorb energy
better than the glass, which is more brittle.  But at least form a glass
blunt edge, and not just an "L" but a closed tube.  The softness of the
surface doesn't mean much, just makes you feel better before the crash.  You
need something that is not sharp and will deform to absorb energy.  Real
energy absorbing foam from a car interior might not be practical as these
are typically molded on to the substrate.

2.  Make a knee bolster at the bottom of the panel.  I plan to NOT place
switches in that position, but provide a "lump" that is also rounded and
will absorb energy.  The protrusion should be enough that your knees can't
touch any instrument knobs, switches, etc.

3.  On my ES I added a few unidirectional Kevlar strips to the forward part
of the fuselage in "X" patterns to act as energy absorbers.

4.  I think the seat mounting is particularly bad (in the ES/IV at least) in
that it is right on the main structural carry-throughs and there is no
energy-absorbing distance below the seat.  In a plane crash I think you need
to worry about the vertical whereas in a car you mostly just worry about the
longitudinal forces.  I was told once that the average plane crash is 15
degrees down.

Is all this too much?  In a real crash, there is no such thing, but how far
do you go?  It is a matter of judgment, I guess.

Gary Casey
ES project, so far no "incidents", max airspeed to date - 0