Pilots flying Blind

One day at a busy airport, the passengers on a commercial airliner
are seated waiting for the pilot to show up so they can get under
way.The pilot and copilot finally appear in the rear of the plane and
begin walking up to the cockpit through the center aisle. Both appear
to be blind; the pilot is using a white cane, bumping into passengers
right and left as he stumbles down the aisle. The copilot is using a
guide dog. Both have their eyes covered with sunglasses.At first, the
passengers do not react thinking that it must be some sort of
practical joke. After a few minutes though, the engines start
revving, and the airplane begins moving down the runway.The
passengers look at each other with some uneasiness. They start
whispering among themselves and look desperately to the stewardesses
for reassurance.Yet, the plane starts accelerating rapidly, and
people begin panicking. Some passengers are praying, and as the plane
gets closer and closer to the end of the runway, the voices are
becoming more and more hysterical.When the plane has less than twenty
feet of runway left, there is a sudden change in the pitch of the
shouts as everyone screams at once.
At the very last moment, the plane lifts off and is airborne.Up in
the cockpit, the copilot breathes a sigh of relief and tells the
pilot: "You know, one of these days the passengers aren't going to
scream, and we aren't going to know when to take off!"