Airline passengers suffered a day of delays and frustration as a telephone system glitch at air traffic control caused major disruption at airports across the UK and Ireland.
Heathrow Airport was the worst affected, with 228 cancellations. At Stansted Airport, flights were delayed throughout the whole day. The average delay was two hours, a spokesperson said.
Eurocontrol, the European organisation for air navigation safety, said it had been working with Nats and its counterparts in Holland and France during the day.
It said about 1,300 flights, nearly 8% of all traffic in Europe, had been "severely delayed."