A computer glitch that caused disruption across several UK airports has been "rectified," the chief executive of the National Air Traffic Services said.
Richard Deakin said that the problem was caused by a single line code in a computer system at the U.K.'s national Air Traffic Control (ATC) centre on Friday, reported the BBC.
However, he warned that upgrading some of its "elderly" systems posed a "challenge."
Almost 40 flights were cancelled at Heathrow as passengers faced widespread disruption on Friday.