As a pilot I get sick of hearing the term "human error" whenever an accident investigation releases their report. Almost every possible scenario can get traced back to human error in one way or another: pilot failed to initiate proper emergency procedures, pilot failed to stop when he should have stopped, pilot failed to go when he should have gone, and pilot was looking left when he should have been looking right. It is almost too easy to investigate an accident while flying at zero knots and determine that had the pilot done something differently maybe that accident wouldn't have occurred. As long as airplanes are piloted by humans then all accidents will have a cause associated with human error in one way or another. In fact, even when airplanes are not piloted by humans their accidents will still be human error because it is difficult (ok, impossible...