Message from the Editor: Though these incidents are all airline related, the systems involved are now also used in GA and could cause accidents.

Autoflight control modes generally involve interrelated functions of the Flight Management System (FMS), the flight director, the autopilot and autothrottles. The mode logic controlling the combined input of these systems can be very complex. Despite focus on design improvements and training emphasis on flight management modes, ASRS continues to receive a significant number of incident reports on mode related errors. While they usually result in minor “altitude busts” or crossing restrictions not met, mode errors can also lead to more serious outcomes including Controlled Flight Toward Terrain (CFTT).