The UK's main air traffic control centre was back to full operation this morning after engineers fixed a computer glitch last night that saw more than 88 flights cancelled and over 10,000 passengers delayed.
The problem started when a fault occurred at one of the systems that feeds the London Area Control Centre at Swanwick in Hampshire.
A spokesman for the National Air Traffic Services (NATS), which runs the centre, said: "The situation was resolved at 7pm yesterday evening. We are investigating what caused the fault and we sincerely apologise for any inconvenience to travellers."
The fault imposed restrictions on the number of aircraft entering UK airspace through London Area Control sectors - airspace 24,000ft above England and Wales - and those taking off from major UK airports.
Flights into and from all London area airports were affected. NATS said that Scottish airspace, Manchester Area airspace and Manchester and London Terminal Control airspace operated normally throughout the night.
Swanwick unveiled a £50m system upgrade in March last year amid complaints from some controllers that the new system was difficult to handle.