Wind-optimal ats route redesign: A methodology and its application to route a461 in china

Due to airspace restrictions and limited availability of navigational aids, ideal direct Air Traffic Services (ATS) routes are usually difficult to achieve in real operations. Moreover, aviation is a fast growing industrial sector causing congestion of the airspace. Hence, in order to improve the flight efficiency and approximate the optimal performance, the redesign and optimization of the ATS route network is required. Route optimization on a tactical level taking into account wind, as one of the most influencing factors, has been broadly discussed in the literature. In contrast, here we present a methodology, which aims at redesigning ATS routes on a strategic level, considering wind situations of a whole year. To achieve this, the average air distance, e.g. the distance corrected by wind effects, along the route has to be minimized. The methodology is then applied to a segment of the Chinese ATS route A461. Since there are several different aircraft types operating on this route, the fleet mix is analyzed to determine typical cruise flight conditions on that route. For the optimization, graph theory based techniques are applied in which a high resolution graph is modeled as search space for the optimization. Assuming mean altitude and mean cruise speed, the air distances between all nodes of the graph are computed for every day of the year 2014 based on wind data from the ECMWF. The air distances of each connections are then averaged and used as cost function within a Dijkstra Algorithm, which is applied in order to obtain annually and quarterly optimized routes. Subsequently, the efficiency increase of the resulting tracks is compared to the theoretical average potential of a tactical daily-based route optimization scenario. Furthermore it is examined, whether the obtained tracks optimizing the year 2014 would have offered efficiency increases for the years 2012 and 2013 as well, in order to estimate a possible long-term feasibility. Finally, an analysis of the tracks in the terms of flight performance is carried out to quantify possible fuel savings.