Computer failure at an air traffic control center in London caused the city's airspace to become restricted this afternoon, leading to "potentially severe" flight delays at Heathrow. The air traffic controllers would only confirm that there had been a "technical problem" that it mobilized a team of engineers to address. About an hour after confirming the incident, the systems were restored. "We apologize for any delays and the inconvenience this may have caused," the controller, NATS, says in a statement.
The air space remains open, but flights aren't taking off
Airspace around the city was briefly closed, but NATS has since revised that decision and is now calling the air space open with restricted traffic volumes. That appears to mean that flights already nearby are clear to land, but that none are able to take off. Heathrow confirmed that it has no scheduled departures or landings because of the incident, thus leading to delays for its fliers. You can see the current state of the airspace around Heathrow update live over at its website. Following the restoration of its systems, NATS says that it's working to return to normal operations, though it did not provide a timeframe.
The Wall Street Journal reports that the air traffic control center, located in Swanwick, went offline after a power outage, and that the disruption may last until 7PM local time. It's unclear if the disruption will lift sooner now that the computers are back online, but flights are already being delayed because of the outage. That's a big issue for fliers at Heathrow, which is among the busiest international airports — and one that wants to grow even bigger. Amid the outage, Heathrow said that some flights were seeing "severe disruption."