Single European sky or SES

The systems established under Regulation (EC) No 549/2004 (37) (EC) No 550/2004 (38), (EC) No 551/2004 (39), and (EU) 2018/1139 of the European Parliament and of the Council to reinforce air traffic safety standards, to contribute to the sustainable development of the air transport system and to improve the overall performance of air traffic management and air navigation services for general air traffic in Europe.