An airplane is boarding. When all the passengers are seated, the copilot comes aboard. He's got a white stick and dark glasses on. He stumbles into the cockpit. There's murmuring amongst the passengers.
One of the stewards takes the intercom. "Ladies and gentlemen, you may have noticed that the copilot is blind. There is no need to worry, he is a very experienced pilot and has 5000 hours of flying behind him".
The passengers setlle down. Just then the captain gets on board. He's got dark glasses and a guide dog with him. He feels his way up the aisle and goes into the cockpit. Again, the passengers are anxious.
Again, the steward takes the intercom. "Ladies and gentlemen, you may have also noticed that captain is blind. Please don't worry, he is a very experienced pilot and has 10,000 hours of safe flying behind him".
The passengers settle down. A few minutes later the plane starts rolling down the runway. It's gathering speed, but the plane isn't rising. About halfway down the runway, the passengers start shouting. Still the plane doesn't take off. The passengers are getting very worried and are shouting and crying. The plane continies to gather speed. Now the passengers can see the end of the runway and some buildings at the end, but the plane doesn't rise. By this time the passengers all start screaming. Right at the end of the runway, the plane picks off the runway and safely into the air, just.
The captain turns the copilot. "You know, the day they stop screaming, we are buggered".