IBM Active Protection System Approach

[M. Warner Losh]

In message: <430A8E2B.6040408 at elischer.org>
            Julian Elischer <julian at elischer.org> writes:
: You have about 1/4 a second to get the heads in once you detect that
: you are falling.

Yes.  For a 4' fall, we know it takes 1/2 a second to reach the
ground:
	s = 1/2 a t^2 + v0 t + s0

s0 = 0, a = 32 f/s^2, v0 = 0, s = 4, solve for t gives 1/2 a second to
make the fall.  Sos was saying 10's of ms to retract the heads, so
even a 300ms response time wouldn't be fatal, but it would be pushing
the limits.

For a 2' fall, you have even less time.  More like 350ms.  1' is 250ms...

Warner