It is said that a Gnat student managed to get lost at night....
....whilst taxying at Valley. For those who've never flown it, you sit so close to the ground in a Gnat that you cannot see very far. This chap turned onto some piece of tarmac which proved itself not to be the taxiway when grass appeared dead ahead. So he shut down, which meant no radio. Or lights. He then got out and made his way to the tower...
"Where did you leave it?"
"Errmm - don't know. On some bit of tarmac on the airfield!"
As it was very dark, they couldn't run the risk of someone running into the abandoned Gnat, so people were diverted until dawn revealed wherever it was that our hero had left it.