Pilot motion perception and control during simulated decrab maneuver

A set of experiments were conducted on the National Aerospace Laboratory (NLR) GRACE research flight simulation facility to determine the effects of sway, yaw and roll motion on perceived motion fidelity, motion perception, pilot workload and pilot compensation. Fourteen pilots were asked to perform a manual decrab maneuver when the aircraft was on final approach with a 30 knots crosswind. Platform yaw, sway and roll motions were varied independently to examine their relative contribution to the pilot's judgements on perceived motion cues and workload. To determine possible effects of workload on the pilot’s opinion about motion fidelity and perception of motion, pilots were grouped in pairs. For each simulator run, one pilot was asked to fly the aircraft while the other pilot was asked to monitor the maneuver. Both pilots answered the same questionnaire after each run. The results show that perception of simulator motion was positively affected by platform sway for both pilots-flying and pilots-not-flying. Platform roll had only a main effect on the perceived motion of the pilots-not-flying. Platform yaw motion seemed to have a positive effect on motion perception only in the absence of platform sway. The pilot motion fidelity ratings show that platform sway improved the fidelity ratings for the pilots-not-flying only. Platform roll (in the absence of sway) also showed to have a positive effect on pilot fidelity ratings. On average, pilot fidelity ratings were higher when the pilot was controlling the aircraft. Handling qualities results show that pilots felt less compensation was required when platform sway was present. This was confirmed by the decrease in pilot pedal and column activity when platform sway was present. The results of the experiment as described in this paper will support our previous studies in the development of objective evaluation criteria for the optimisation of simulator motion cues.