Autoflight systems in the current generation of aircraft have been implicated in several recent
incidents and accidents. A contributory aspect to these incidents may be the manner in which
aircraft transition between differing behaviours or “modes.” The current state of aircraft
automation was investigated and the incremental development of the autoflight system was
tracked through a set of aircraft to gain insight into how these systems developed. This process
appears to have resulted in a system without a consistent global representation.National Aeronautics and Space Administration under grants NAG1-1581 and NAG-1-1857. Support was also provided by FAA and NASA Grant FAA-95-G-017
