The technical glitch which caused widespread disruption to flights last week was a "one in 15 million" occurrence, an air traffic control (ATC) boss said.National Air Traffic Services (Nats) chief executive Martin Rolfe said one of its systems failed after it "didn't process (a) flight plan properly".

The technical glitch which caused widespread disruption to flights last week was a "one in 15 million" occurrence, an air traffic control (ATC) boss said.National Air Traffic Services (Nats) chief executive Martin Rolfe said one of its systems failed after it "didn't process (a) flight plan properly".