NATS issues cause widespread flight disruption

The air traffic provider for the whole of the UK, NATS, suffered a mass outage on Monday, August 28, causing mass cancellations at airports globally.

NATS first announced the issue shortly after midday on August 28, and said it had “applied traffic flow restrictions to maintain safety.”

At 1420hrs local time it released a further update, in which it said the issue affected its “ability to automatically process flight plans.” NATS added: “Flight plans are being input manually which means we cannot process them at the same volume, hence we have applied traffic flow restrictions.”

At 1515hrs local time, NATS said it had “identified and remedied the technical issue,” and was working closely with airlines and airports to manage affected flights “as efficiently as possible.” It also said its engineers were to monitor the system’s performance as normal operations were resumed.

Heathrow Airport was the worst affected airport, followed by Gatwick and Manchester.
Heathrow Airport was the worst affected airport, followed by Gatwick and Manchester. Heathrow Airport

On Tuesday, August 29, Heathrow Airport, the UK’s busiest airport, said on its website: “The technical issue which limited UK air traffic yesterday has been fixed by NATS. However, schedules remain significantly disrupted. We ask passengers to only travel to the airport if their flight is confirmed as still operating. We are working as hard as we can to minimize the knock-on impacts and assist those who have been affected.”

Flights arriving into the UK were also affected, and BBC sports presenter Gabby Logan posted on their X, formerly Twitter, account: “On a plane on the runway at Budapest airport. After almost 3 weeks away from home I am hours from hugging my family. And have just been told UK airspace is shut. We could be here for 12 hours. So we sit on the plane and wait.”

In the wake of the outage, aviation analytics firm Cirium said that 790 departures from the UK were cancelled, amounting to 27%, and 785 arrivals were cancelled, again 27%. It said Heathrow was the worst affected airport, followed by Gatwick and Manchester.

Although the outage lasted a couple of hours, disruption was expected to last for a couple of days after. In a video posted to NATS’ website Juliet Kennedy, Operations Director at NATS, said: “Our teams worked hard to resolve the problem…however, it will take some time for flights to return to normal, and we will continue to work with the airlines and the airports to recover the situation.”

An investigation into the cause has been launched, though as reported by the BBC a spokesperson for the Prime Minister said “the information we have is that there was not a cyber-attack.”