The European Commission is taking to task the vast majority of its 27 nation states for their lack of progress in forging the Single European Sky through a program to unify regional airspace.

Inefficiencies caused by Europe’s fragmented airspace generate extra costs of close to €5 billion each year, adding 42 kilometers (27 miles) to the distance of an average flight, and forcing aircraft to burn more fuel, generate more emissions, pay more in user charges and incur delays. The U.S. controls the same amount of airspace, with more traffic, at almost half the cost.

Late last year, Brussels vowed to launch infringement procedures against the European nations that had failed to fulfill requirements to make nine Functional Airspace Blocks (FABs) fully operational.

In an address delivered to a recent air traffic management conference, European commissioner for transport Siim Kallas repeated the EC’s concerns about the late delivery of such an important aspect of the Single European Sky program. That came only days after the airline industry branded as a retrograde step the decision by the European Single Sky Committee to endorse weakened future performance and charging rules for air navigation services to apply between 2015 and 2019.

An official with one European nation’s aviation regulator confirmed to AIN that the commission has started a procedure called the EU Pilot, a pre-formal infraction process under which Brussels is requesting 25 out of 27 states answer specific questions about the lack of progress.

“If all the issues and questions can be answered at this stage it avoids formal infraction,” said the official, who noted that although the questions relate to the lack of progress on developing cross-border airspace blocks, the Commission can carry out proceedings only on a national basis.

The national regulators of ATC agencies will now rely on their respective service providers to answer those questions and to detail their plans for delivering greater benefits in the future. The respondents must file their answers by mid-April, although the commission might honor requests for extensions.

In terms of future performance and charging rules, the official said that arriving at the final text to which all the states agreed proved a “long and difficult” process, complicated by the commission’s efforts to promote the views of the airspace users as well as its own ambitions.

“The member states meanwhile worked hard to provide something that would be challenging but achievable,” he said. “There was real concern at the start shared by all the member states–on hearing the language being used–that actually ‘challenging’ was approaching the ‘unachievable.’ The user community will probably share a different view but in my view we now have a regulation that was better than before, that we can now work with over the next year to set challenging but achievable targets.”