The growth in air traffic worldwide represents a challenge to the safety of this mode of transport. The risk per flight has remained constant. The objective that civil aviation authorities in France and around the world have set themselves for the coming years is a higher level of air traffic safety. Research continues to improve in particular the safe functioning of installations, the operational efficiency of control throughout all phases of flight and the tools used in airports in order to make the most of air-ground data links like the gate to gate concept developed in Europe by Eurocontrol.