Travellers faced hours of delays at Gatwick Airport on Saturday after a system outage grounded flights.
Passengers flying to and from the West Sussex airport reported planes being stuck on the tarmac after the problems hit at around 8am.
The airport said the air traffic control outage had since been fixed, but apologised for ongoing delays.
Dozens of departures and arrivals appeared to be affected, with football fans travelling to Premier League matches among those experiencing issues.
Danny Bellringer, 45, was travelling from Dublin with fellow Brighton fans for the game against Burnley when the group was told their Aer Lingus flight would be delayed by at least two hours.
The oil rig worker said: “There’s not a huge amount we can do – we’re kind of used to it when travelling over from Ireland to the UK for games, (it) very rarely goes completely smoothly.”
Padraic Mac Aonghusa, 24, said fellow passengers on his Ryanair flight from Dublin were “angry” when the pilot announced there would be a delay due to the issues at Gatwick.
Mr Mac Aonghusa, who works in finance in Ireland, was travelling for the game between Crystal Palace and Liverpool and was delayed for an hour and 15 minutes.
A London Gatwick spokesperson said: “There was an outage to a local Nats system earlier this morning which has now been rectified.
“Some passengers may experience delays. We apologise for any inconvenience.”
The spokesperson added that one flight was cancelled and two were diverted from Gatwick.