Simulated Flight Trial Assessment of Novel Autorotation Cueing Methods using a Head Down Display

Abstract

Autorotation is an emergency maneuver executed by helicopter pilots usually following a loss of power, mechanical or system failure. The pilot is required to perform several tasks simultaneously and the timing of each of these must be precisely controlled. Workload can be high throughout the maneuver and the consequences of getting things wrong can be serious, if not fatal. Following on from a series of studies that investigated the use of both head-up displays and haptic cueing methods to assist pilots to fly the maneuver more safely and consistently, this paper presents a pilot-in-the-loop flight simulation study to explore the use of pilot cues provided on a head-down display. These provided pitch angle (and hence airspeed) cueing to the pilot. The cueing symbology was tested for a straight-in autorotation approach for a number of different visual environments and the results compared to equivalent cases where no cueing was present. The cues were assessed both subjectively, via pilots providing Bedford Pilot Workload Ratings, as well as objectively, via analysis of the flight path performance achieved. The subjective evaluation showed that cues using the head-down display were useful in terms of pilot workload reduction, particularly for the degraded visual environment scenario tested. The objective assessment revealed that pilots were able to establish the steady state descent more quickly and maintain forward airspeed within the specified bounds more reliably with the aid of the cues.