"A Single Market, A Single Currency, A Single Sky?
Europe eliminated frontiers on the ground with the 1985 single European market. It dismantled economic frontiers with the 1990 economic and monetary union. It is a view widely held that borders in the sky should not exist.
In spite of much effort to modernise and streamline it, Europe’s air traffic management system remains safe but fairly costly. It is also hampered by heterogeneous working practices and constrained by air route networks which, in the main, are based on national borders and not air traffic flows.
The Single European Sky initiative puts forward a legislative approach to solving the issues that currently affect air transport as well as enabling ATM to cope with future demands."