A weatherman in Australian named Grant Denyer did a segment from the passenger seat of a stunt plane Tuesday morning.  And in the middle of it, the G-forces got to him and made him PASS OUT on live TV.  He was only unconscious for a few seconds, but you can check out the video online.  According to the pilot, they were experiencing about 8 G's when it happened . . . meaning 8 times the force of gravity.  Here's a clip.  (--The pilot is the one talking the whole time.)