Holidaymakers have been warned that delays could continue for days after an air traffic issue downed flights over London airspace.
Hundreds of flights were delayed after the air traffic control (ATC) system went down for about 20 minutes on Wednesday July 30.
Now, the system is back up and running but the incident could cause a backlog of delays in the busy summer holiday period, it has been warned.
Here is all we know about the incident:
What happened?
Thousands of passengers were left stranded on runways after planes at major UK airports had to be grounded following a technical glitch at air traffic control.
No planes were able to take off for 20 minutes at airports across the country following an issue at a control centre in Hampshire at around 4pm on Wednesday, creating a backlog of delays during the busy summer period.
Nats, the company that runs the system, said there had been a radar failure, which was resolved by quickly switching to a backup system.
But furious airlines said more needs to be done to stop it happening again, as a similar incident in August 2023 saw a system failed again, leaving hundreds of thousands of passengers’ flights delayed or cancelled.
How long will delays last?
Transport secretary Heidi Alexander said “continued disruption is expected” and urged passengers to “check with individual airports for advice” after thousands of passengers were left stranded across Europe.
Aviation experts warned delays could be experienced for days.
What have airlines said?
They are not happy and want assurances it will not happen again.
EasyJet's chief operating officer David Morgan said: "It's extremely disappointing to see an ATC failure once again causing disruption to our customers at this busy and important time of year for travel.
"While our priority today is supporting our customers, we will want to understand from Nats what steps they are taking to ensure issues don't continue."
Ryanair chief operating officer, Neal McMahon called for Nats' chief executive Martin Rolfe to resign in the wake of the fault.
He said: “It is clear that no lessons have been learnt since the August 2023 Nats system outage, and passengers continue to suffer as a result of Martin Rolfe's incompetence.
"If Nats CEO Martin Rolfe fails to resign on the back of this latest Nats system outage that has disrupted thousands of passengers yet again, then UK transport minister Heidi Alexander must act without delay to remove Martin Rolfe and deliver urgent reform of Nats' shambolic ATC service, so that airlines and passengers are no longer forced to endure these preventable delays caused by persistent Nats failures."
Am I entitled for compensation if my flight was delayed or cancelled?
Passengers are unlikely to get any compensation from this incident, say experts.
Consumer group Which? said the technical issue could be classified as an “extraordinary circumstance” that was out of airlines’ control.
This means airlines do not have to pay out.
Naomi Leach, of Which? Travel, did however say that travellers could have the right to food or a hotel stay, depending on the length of delay.
She said: "If you are due to travel today or tomorrow, check the advice from your airport or tour operator, or airline apps and airport social media feeds, for the most up-to-date advice."
