The votes are in, and an honorable mention for the classic from Dan Gerous:
"When I grow up, I want to be a pilot.
You can't do both son."
But the winner is MPN11 with :"The CAA and FAA immediately expressed grave concern about the number of seat cushions that would be required."
The CST is in the virtual courier to you now........
(I was expecting someone to maybe try "Children of the magenta line" or similar
)