A week-long IT glitch at Frankfurt, Germany's busiest airport, caused about 68 flights a day to be cancelled. The answer lay in returning to a previous version of its air traffic control software.
The German air traffic control agency said airspace around Frankfurt, Bonn-Cologne, Stuttgart and Dusseldorf had returned to full capacity on Thursday. It reduced capacity at the airport to 75 percent last Wednesday for safety reasons.
The agency said other air traffic control centers in Germany were not affected.
The German flight safety agency fixed the problem by reinstalling an older version of the area's traffic control software on Wednesday night and then cleared the airport to return to full capacity.
The February software update affected the system that communicates data such as aircraft type, route and expected time in local airspace to air traffic controllers.
About 68 of the 1,400 daily Frankfurt flights had to be cancelled due to the problem.
Most airlines said they had managed to get by without severe disruptions as they were operating reduced winter schedules.
ta/jm (dpa, AP)