The European Commission has urged several EU member states to make good on promises regarding shared airspace. Germany, Belgium, France, the Netherlands, and Luxembourg have been urged to implement their Functional Airspace Block (FAB), a supra-national airspace area that all EU countries were supposed to have adopted by the end of 2012. “Right now these common airspaces exist only on paper; they are formally established but not yet functional,” said commission vice-president Siim Kallas. Europe’s nine FABs are a cornerstone of the EU’s Single European Sky initiative, which is designed to introduce significant efficiencies into European air navigation. The present system, in which airlines are handed over to a different air traffic control regime at each national border, is estimated to cost the industry €5bn ($7bn) per year in inefficiencies. The commission has also said that six other FABs, including UK-Ireland, are not fully compliant with EU regulations.