Flight Evaluation of Helicopter Curved Point-in-Space Approach Procedures

Abstract

Helicopter point-in-space instrument procedures are key to enabling simultaneous noninterfering procedures and enhancing all-weather access in dense airspace and remote locations. This paper describes the flight evaluation of navigation and human performance in helicopter curved point-in-space procedures as part of Single European Sky Air Traffic Management Research. An experimental procedure was designed at Donauwörth heliport including radius-to-fix legs with descent gradients and airspeed variations in the terminal segments, followed by a steep, straight-in final approach segment. Two strategies were evaluated for vertical descent profiles: fixed flight path angle, and fixed vertical speed. Three test pilots were instructed to execute the entire approach until the missed approach point in simulated instrument meteorological conditions using advanced autopilot modes and head-down flight and navigation displays. Navigation performance was measured using cross-track and vertical-track deviations. Pilot workload and situational awareness were measured using the task load index and the situational awareness rating technique, respectively. The results showed that flight paths were maintained within the required navigation performance limits despite strong crosswinds, and the final approach glidepath was successfully captured in all cases. All pilots reported low workload, adequate spare capacity, and high situational awareness in all cases. Furthermore, the fixed flight path angle descent was found to induce lower workload and required fewer crew actions compared with the fixed vertical speed descent. Owing to the small sample size, conclusions with statistical significance cannot be established.