Britain's main air traffic control centre was back to full operation tonight after engineers fixed a computer glitch that saw scores of flights cancelled and delayed.
However, Ryanair and Aer Lingus have advised that some flights tonight may have to be cancelled.
The problem started just before 4pm today when a fault occurred at one of the systems at Swanwick Air Traffic Control Centre in Hampshire.
This led air traffic control company NATS to restrict the number of planes entering UK airspace as well as those taking off from major UK airports causing serious disruption.
But a NATS spokesman said that the problem was now resolved.
While engineers worked to fix the fault controllers operated with manual
systems at a reduced capacity.
Only sectors controlled from the London area control centre were affected.
The airports affected included London Heathrow, London City, Gatwick, Stanstead, Luton and Cardiff.