Originally Posted by
Genghis the Engineer
A human being will take a 26g impact - but only if the seat structure is designed to absorb a reasonable proportion of the energy.
I would imagine that in a 26G forward impact, ones neck would be broken by the inertia of ones head. That's why racing drivers wear those braces that attach their helmets to their shoulders.
Cirrus seem to have the safest design for a vertical impact: honeycomb aluminium seat squabs that progressively collapse, after the aircraft has hit the ground under the parachute. However, that only works if you haven't already squashed them by kneeling on them ...