What a joke! The BIGGEST issue is the little state monopolies (ANSP's) and the unions that do EVERYTHING to stop a proper single sky being introduced...
Solution:
-One network manager who has proper control over the sky: EUROCONTROL
-The same overflight rates all over Europe
-No more local inefficient ANSP's (DFS in Karlsuhe should be the first one that should be fired!)
-One system all over Europe
-Good salaries but only strikes over really important things
-High quality training all over Europe to ONE standard
-Training more controllers
In short: a real single sky like in the US......