I saw a show on TV where some guy modded a military steam catapult with a padded seat, and he launched himself off of a huge cliff. The plan was to ride the catapult off the cliff and parachute into the ocean near some boats or if he found lift, glide to the beach.
Despite a lot of padding, finding a good sitting position and wearing some protective gear, the launch fractured his back and neck in a few places so he was instantly in nearly crippling pain before he left the seat. He managed to get his chute open but glided straight ahead and had to be pulled out of the water then carried to an ambulance.
If he'd had any brains, he would have first requested the ejection and acceleration test data done on humans by NASA, the USAF, and other research labs, and discovered that the accelerations he was going to experience were high enough to cause severe injuries. But reading a book and cancelling the cat shot would have made for a boring tv show, so...
