A Graph Search-Based Trajectory Optimiser for Practical Wind-Optimal Trajectories

As air traffic management moves towards trajectory-based operations, route flexibility will increase and aircraft will be less constrained by the current fixed air traffic services route network and airspace structures. To gain maximum benefit from this increased flexibility, it will be necessary to plan so-called “wind-optimal” tracks that take account of wind, especially for medium- and long-haul flights. The Electronic Navigation Research Institute (ENRI) has developed a dynamic programming-based trajectory optimiser that can generate ideal wind-optimal trajectories for research purposes, but its high computational burden and the difficulty of applying operational constraints mean that it is not suitable for creating practical flight trajectories. We are therefore exploring alternative means of creating practical wind-optimal trajectories. In this paper, we describe a proof-of-concept program that represents possible aircraft lateral routes as a graph and calculates wind-optimal trajectories by a shortest-path search using fuel consumption or flight time as a metric instead of distance. We present preliminary results of track computation assuming constant altitude and airspeed in the north Pacific free route area, and show a sample qualitative comparison with Pacific Organised Track System tracks and an actual flight track that demonstrates the potential feasibility of our approach.