There's a story about a USN squadron at Guantanamo Bay when it was still a US airbase. They were due to return to their base on the East coast. One of the big (300 gallon?) drop tanks carried on the centre line of their A4's was steam cleaned and filled with good Cuban rum at some derisory price. The fuel transfer switches were firmly wire locked off and the aircraft set off. The pilot had to stop off on the way for fuel, and to clear customs. He got back to his aircraft just in time to see the refueller screwing the top back on the tank with the cheery cry of "It was nearly full, sir, but I topped it up anyway"