A power failure at a control center in England is the reason for an interruption in London’s airspace and some major delays are expected once it reopens.
Bloomberg News noted that National Air Traffic Services said the Swanwick air-traffic center experienced a technical glitch and officials hope to reopen the airspace by 7 p.m. local time (2 p.m. EST).
Huge delays are already being felt at London’s Heathrow Airport.
"Flights are currently experiencing delays and we will update passengers as soon as we have more information," Heathrow Airport spokeswoman Marianna Panizza told CNN.
The international airport located in West London, is the busiest in Europe by passenger traffic with around 1, 300 flights arriving and departing each day and flights to 170 destinations worldwide.
In addition to Heathrow, Gatwick Airport said that it will allow arriving flights, but all departures would be put on hold. Stansted Airport also said that it will suspend all departures.
Manchester Airport reported that it would prepare to accept some diverted fights.