The UK’s National Air Traffic Services (NATS) said the technical fault was “identified and remedied” on Monday evening, but “significant disruptions” are set to continue over the next few days as airlines work to clear the flight backlog. 

The technical problem was revealed at 12.15pm on Monday, causing staff to have to input flight plans manually until the automatic system was recovered at 3.15pm. 

The network-wide outage caused the worst day of flight disruptions in the country since the eruptions of the Icelandic volcano Eyjafjallajökull in 2010. In total, 790 departures and 785 arrivals were cancelled on Monday, according to flight analytics company Cirium. The number is equivalent to around 27 per cent of planned flights to and from the UK. 

“[The fault] was fixed earlier on this afternoon,” said Juliet Kennedy, NATS operations director, on Monday evening. “However, it will take some time for flights to return to normal, and we will continue to work...