Originally Posted by
Sprogget
Carabiner failure is so rare no one designs for it. Those guys were unlucky, The Hang glider pilot was negligent .
As a climber, I would always use 2 screw-gate carabiners positioned so that their gates are on opposite sides for critical attachments. Also, if you have a backup attachment, you always arrange them so that if one fails the load is smoothly and 'fairly' transferred to the backup - ie avoid slack which creates massive snatch loads and ensure that the load will come down the length of the crab and not sideways.