On Mar 21, 6:00*pm, bildan wrote:
It's not hard to ascribe the other 5% to pilots as well since
the pilot is charged with insuring his (it's usually guys) aircraft is
airworthy.

An airworthy spar in a glider flown by a well trained pilot who knows
and follows the rules has a 0% chance of breaking.

Wait. If pilot n-1 overstresses said spar, then chances of it breaking
may be closer to 100% for pilot n. Yet, the damage may well be
invisible and impossible to detect during normal preflight. Are you
saying that if pilot n gets killed then it is his own fault for not
properly x-raying the wings before flying?

B.