EU nations on Tuesday missed a key deadline in a decade-long drive for a safer, cheaper, more climate-friendly \"single\" European sky, triggering warnings by Brussels of imminent legal action. Speaking on a day meant to mark a breakthrough in efforts to create a functional common airspace, Europe\'s transport commissioner Slim Kallas threatened European Union nations with court action and fines for failing to honour their obligations under the scheme. \"We will take every possible action to make the single European sky a reality,\" he said. \"At a time of economic crisis we cannot afford to live with the status quo.\" At stake was a bid to redesign the EU\'s 27 national airspaces into nine sectors and to have these -- known as Functional Airspace Blocs (FABs) -- fully operational by Tuesday. If the EU were to succeed in re-designing its airspace, it could triple its airspace capacity, improve safety ten-fold, slash pollution by 10 percent and reduce air traffic management costs by 50 percent, the Commission said. US airspace in comparison is roughly the same size as Europe\'s. But where Europe has more than 30 air navigation service providers, there is just one in the United States, which serves twice as many flights at around the same cost. In an angry statement, the European airline industry also condemned EU states. \"The current situation is scandalous,\" said the Association of European Airlines (AEA) in a joint statement with regional and low fare companies as well as the International Air Carrier Association (IACA). \"We are dismayed that lack of political will by member states has stalled any hoped-for progress,\" it said. \"We therefore urge Transport Commissioner Kallas to follow up on his warning ... and launch infringement procedures against defaulting states.\" \"The costs of congestion and delays in the air are paid for on a daily basis by European citizens and business,\" said Kallas. \"Right now the implementation of the reform of Europe\'s airspace is falling seriously behind,\" Kallas said. \"A critical deadline has been missed. There is no other option but to strongly enforce EU law.\" It was not his first threat of taking legal action against EU governments, but this time the European Commission pledged it would \"proceed shortly by sending letters of formal notice to all parties concerned.\" An EU source said that the letters, the first step in infringement proceedings, would be sent in February or March. No details were available on the names of the \"many\" member states slammed for \"seriously lagging behind\" in efforts to get the scheme going. But last month the Commission said that only five nations -- Belgium, Denmark, Lithuania, Luxembourg and the Netherlands -- were on track to meet cost cutting targets and improving flight capacity. The commission estimates that the current patchwork system of national airspace results in an additional cost to airlines of around five billion euros ($6.4 billion) a year. EU airspace is divided into 650 sections run by 60 air traffic control centres and managed by national systems, with little real cross-border management from coordinators. Air traffic control currently represents between six and 12 percent of the price of a plane ticket, to which are added the rights to take off and land, and from next year, an EU tax on airline pollution emissions. Because of the fragmentation, aircraft are forced to cover longer distances over \"bizarre routes\" since controllers cannot handle more than a certain number of flights at one time, the EU source said.