Use of advanced airborne weather radar for flight trajectory optimization

Trajectory of civil aircrafts is typically optimized off-board and expressed in form of waypoints, i.e. latitude and longitude of significant points on the route, along with altitude and speed to be kept. Flight plans are pre-calculated before take off in order to optimize fuel consumption, using the information available from weather predictions. Changes to the route are decided by the pilot during after continuous updating of information during the flight, such as METAR and NOTAM updates. The retrieved updates are also accompanied by the detection of unexpected weather condition detectable from data collected by the weather radar installed on the nose of the aircraft. This weather radar provides to the pilot qualitative information on the presence and intensity or clue of convective clouds along the route. The main purposes of changing a route are: reducing the risks related to the flight and improve passengers’ comfort. Pilot workload and effectiveness of route changes can be reduced having at disposal more reliable information sources (including an advanced – i.e. dual polarization weather radar) and proper software implementing algorithms such as Quasi-Artificial Intelligence or Data fusion for appropriate usage of the information available aboard. These tools allow the pilot to run more sophisticated decision processes that include pollutants, being the most important chemical species emitted by aircraft engines carbon dioxide (CO2), water (H2O), nitrogen oxides (NOx), and sulfur oxides (SOx), and acoustic noise as well. Indeed, aircraft trajectory optimization is highly sensitive to atmospheric conditions; pressure, relative humidity, temperature, wind intensity and direction have various influences on thrust needed and the resulting air pollutant emissions (Serafino et al. 2012). The Management of Trajectory and Mission is a relevant part of “System for Green Operation” activity of the Clean Sky JTI (Joint Technology Initiative) launched by the European Union with the objective of developing breakthrough technologies to significantly increase the environmental performances of airplanes and air transport, resulting in less noisy and more fuel efficient aircraft, hence bringing a key contribution in achieving the Single European Sky environmental objectives. A wrong trajectory management, in response to meteorological hazard detected by the weather radar, could negatively affect the aircraft optimum route and result in additional fuel consumption and pollutant emission.