45. Doing Loop de Loops With Your Lungs
Some wise guy must have thought this was a funny prank to play, leaving a full, open ashtray lying around to go flying anywhere. The pilot was clearly not amused, and it could have been a pretty dangerous prank, given how it almost ended.
Coughing up a storm while trying to get the plane back in control, vision obscured by the ash on everything. Maybe this is the real reason that smoking was banned on commercial flights. Mystery solved.