The pilot of an aerobatic biplane landed in the recently mown field of a Scottish farmer to make a few adjustments to his engine. While he was tinkering with his machine, he noticed the Scotsman and his wife watching with a great deal of curiosity. The Scotsman asked the pilot how much he would charge to give both he and his wife a ride.
'Well', said the pilot, 'Normally I charge $50 dollars each, but if you are both completely quiet throughout the flight, the ride will be free of charge. If I hear the least amount of noise, you will owe the full fare.'
The couple quickly climbed aboard, and the pilot taxied and took off. Immediately, he proceeded to put his plane through all of its paces: barrel rolls, stalls, spins, split S maneuvers, you name it and he did it. The couple in back were completely silent throughout the thirty minute flight.
Upon landing, the pilot said, 'I really have to hand it to you for keeping quiet through all that!'
'Aye', said the Scotsman, 'but I'll admit, ye almost heard me when the wife fell out.'