Automation in general aviation: Two studies of pilot responses to autopilot malfunctions

Study 1 examined 4 automation-related malfunctions (runaway pitch trim up, roll servo failure, roll sensor failure, pitch drift up) and subsequent pil ot responses. Study 2 examined 4 additional malfunctions, 2 more immediatel y obvious (runaway pitch trim down, runaway roll servo) and 2 more subtle ( failed attitude indicator, pitch sensor drift down) than those in Study 1, and the effect of an auditory warning. Data collection was performed in the Civil Aeromedical Institute's Advanced General Aviation Research Simulator , configured as a Piper Malibu. Results suggest that maladaptive responses to some of these failures may, in a significant percentage of cases, lead t o significant altitude loss, overstress of the airframe, disorientation of the pilot, or destruction of the aircraft. Percentages of successful recove ries, detection and correction times, and related indexes of performance ar e discussed in the context of malfunction type, flight profile, and auditor y alerts.