Heard from a friend of mine:
Student rushing to get into the air, but the tow-bar is still attached to the nosewheel.
He gets out to remove the tow-bar but forgets to shut down (yes he was in that much of a hurry). He only realises this upon feeling the whooshing of air near his head as he's bending down to remove the tow-bar.
My most stupid mistake (so far):
I'm running through my before start checklist. I check the trottle movement and friction by moving it through its full range and leaving it where I found it. After completing the checklist, I start up and the engine roars into life and the airplane immediately starts to try to move. I always start with my toes on the brakes, so it didn't move (much).
As you have probably realised by now, the throttle had been left wide open, and during the before start throttle check, I made the mistake of leaving it where I found it instead of where it should be!
[ 14 August 2001: Message edited by: BayAreaLondoner ]