LONDON (CNN) — A technical issue at the UK’s air traffic control center in Swanwick is causing delays to hundreds of flights Saturday across the United Kingdom, including Heathrow Airport.
“We are currently experiencing some difficulty switching from night time to daytime operation,” National Air Traffic Services (NATS) said in a statement.
“This may result in some delays for which we apologise. Engineers are working to rectify the problem as soon as possible.”
It added, “Safety has not been compromised at any time.”
The NATS center at Swanwick handles flights for much of England and Wales, including the airspace around London which it says is one of the busiest areas in Europe.
Stranded travelers voiced their frustration on Twitter.
“Flight changed and pushed back twice. Delay of just two hours. Let’s hope it stays that way,” said Carolanner.
A Heathrow spokeswoman said, “Flights from many UK airports, including Heathrow, are subject to delay and cancellation. If you are flying today you should check the status of your flight with your airline.”
Airport information boards indicate the problem is affecting departures to a greater extent than arrivals.
Heathrow, to the west of London, is one of the busiest airports in the world, serving 70 million passengers annually according to its website. On average, around 191,000 passengers transited the airport daily in 2012.
Gatwick, Stansted and Luton Airports also serve southeast England. Other busy UK airports outside the London area include Birmingham, Manchester, Glasgow and Edinburgh.
Low-cost airline Ryanair said on its website, “Ryanair has been advised of an equipment failure within UK Air Traffic Control which will cause significant flight delays and possible cancellations.”
Virgin Atlantic said it was “experiencing some delays.”
NATS said the technical problem involved its ability to split out airspace sectors.
“At night, when it’s quiet, we can combine sectors of airspace. When it gets busy in the daytime we split the sectors out again. The voice communications system is configured to enable this to happen,” its statement said.
“We experienced a technical problem in the early hours of this morning, which means that it hasn’t been possible to reconfigure the voice communications system to split out the sectors for the busier daytime traffic in some areas of the UK enroute airspace.”
By Laura Smith-Spark and Bharati Naik