The passengers on the jetliner were relaxing in their seats for the long flight.  The voice over the loudspeaker had just announced that the aircraft had reached its cruising altitude and that the passengers were free to unfasten their seatbelts and move about the cabin.  Then the voice continued.

"Ladies and gentlemen, we are proud to announce that you are flying on the maiden voyage of one of our brand new fully- automated jetliners.  These new jetliners are the pride of our fleet and have no need for pilot, co-pilot or navigator.  All human error has been eliminated.  You needn't be alarmed, as everything from the cabin pressure to the speed and altitude is completely controlled by our computer.  We're excited about the world's first fully-automated airplane, and we hope you are, too.  So just sit back and relax, and remember, nothing can go wrong...  nothing can go wrong...  nothing can go wrong...  nothing can go wrong..."