The British Government has demanded an investigation after a computer failure on Saturday at one of two air traffic control centres caused a major disruption of air traffic into and out of London.
The congested airspace over the British capital was closed during the 35-minute shutdown, leading to severe delays and flight cancellations in London and other parts of Europe.
UK-based air traffic management company NATS said the problems at its control centre in Swanwick occurred as more workstations were being brought online to deal with an increase in traffic. The computer failure made it impossible for the controllers to access data regarding individual flight plans. Planes were prevented from taking off, but those in the air and close to airports were allowed to land during the shutdown.
Problems were particularly acute at Heathrow, Europe's busiest.
The NATS centre at Swanwick has been plagued by problems since it opened in 2002 - six years late and at twice its anticipated cost. Software and reliability issues have caused repeated disruptions since.
