Passengers are facing widespread flight disruption after a computer failure at the UK's air traffic control centre.
National Air Traffic Services (Nats) said a technical fault in the flight data system at its Swanwick centre had caused the problem.
It had now been restored to "full operational capacity", the air traffic control company said.
The government said the disruption was "unacceptable" and demanded a "full explanation" of what had gone wrong.
