Abstract:
The paper describes findings from a rotorcraft pitch-surge motion fidelity study conducted in the University of Liverpool's HELIFLIGHT-R flight simulator. Two test pilots flew a decelerating offshore approach maneuver during which a disturbance was encountered. The approach was flown without simulator motion as a ‘baseline' case and with simulator motion using different combinations of pitch and surge motion filter coefficients. The pilot-awarded handling qualities and motion fidelity ratings for each motion configuration, and task performance and control activity data were gathered. The study concluded that for the approach flown without motion, the dominant driver of workload was vertical rate control, and this was most significant at airspeeds less than 50kts. When the approach was flown with a disturbance, good motion cues were judged to be achieved through careful selection of the pitch and surge motion filter gains, the most favored being a surge gain equal to that of the pitch gain. Additionally, pilots preferred pitch-surge cues that were in the correct sense, rather than being particularly ‘strong'. Increasing the pitch gain was only beneficial with a moderate level of pitch break frequency of 0.4 rad/s.