Flying

One day at a busy airport, the passengers on a commercial airliner were seated, waiting for the pilot to show up so they could get under way. The pilot and copilot finally appeared in the rear of the plane and began walking up to the cockpit through the center aisle.
Both appeared to be blind. The pilot was using a white cane, and bumping into passengers, right and left, as he stumbled down the aisle. The copilot was using a guide dog. Both men were wearing sunglasses.
At first, the passengers did not react, thinking that it must be some sort of practical joke. After a few minutes though, the engines started revving, and the airplane began moving down the runway. The passengers looked at each other with some uneasiness. They started whispering amongst themselves, and looked desperately to the stewardesses for reassurance. The plane began to accelerate rapidly, and people began panicking. Some passengers began praying, as the plane got closer and closer to the end of the runway. The passengers became hysterical, and when the plane had less than twenty feet of runway left, everyone screamed at once.
At that moment, the plane lifted off and became airborne. Up in the cockpit, the copilot breathed a sigh of relief and said to the pilot, "You know, one of these days they aren't going to scream, and we aren't going to know when to take off!"