Eject!

The following link details an RAF pilot's recovery from horrific injuries after a mid-air collision and ejection. His life was saved by, perversely, a weak joint in the chin-strap of his helmet.

http://www.ian-weaver.com/ians_page/accident-10th-jan-1996/comment-page-1/

An amazing read; it is well worth reading the comments as well.