National Air Traffic Services (Nats) has issued a statement confirming a technical problem has been reported at Swanwick air traffic control centre.
According to the Twitter feed of EuroControl, the computer failure is affecting London airspace causing potentially severe delays until 7pm today (12 December 2014).
A Nats statement said: “We apologise for any delays and our incident response team has been mobilised. Every possible action is being taken to assist in resolving the situation and to confirm the details.”
Almost one year ago, Nats outlined plans to look at ensuring 100% contingency in the event of an IT failure.
At the time, Nats chief executive Richard Deakin said: “A public debate has started over the level of contingency Nats had in place for the issue.”
More on Nats
In December 2013, hundreds of flights at several UK airports were delayed or cancelled because of a computer failure at Nats.
The knock-on effects of that failure resulted in the cancellation of 18 flights at London’s Heathrow airport on 8 December 2013, while 228 flights were cancelled the day before, according to the Financial Times.
Following 2013’s computer failure, Nats said: “To be clear, this is a very complex and sophisticated system with more than a million lines of software.
"This is not simply internal telephones, it is the system that controllers use to speak to other air traffic control agencies both in the UK and Europe, and is the biggest system of its kind in Europe.”