A process and system for the planning a cost-minimized aircraft flight route between a starting point and end point takes into account costs associated with the flight route, no-fly zones and flight corridors, and aircraft limitations. A raster set is determined which comprises topographical points between the starting and end points, and costs associated with the respective raster points are determined. N nodes are determined for each raster point of at least one subset of the raster set, such nodes being associated with approach directions of the raster point by the aircraft. Possible take-off directions of the raster point are defined, taking into account the minimum turning radius of the aircraft, as a function of the approach direction. A cost-minimized flight route is determined by means of a shortest path algorithm, taking into account only the k most cost-effective nodes (k