Nats was forced to tell passengers to check with their airlines to see if their flight was still going ahead after temporary flight restrictions were imposed at the airport, the BBC reported.
In a statement, British Airways said: “Due to air traffic control restrictions imposed on all airlines at Heathrow, which limits the number of aircraft which can safely take off and land per hour, we’ve had to make some adjustments to our schedule.
“We’re really sorry for any disruption this may cause.”
Meanwhile, Nats told the BBC: “We are working hard to minimise disruption, working closely with Heathrow airport and airlines. Passengers should check the status of their flight with their airline.
"Restrictions of this sort are only ever applied to ensure safety and we apologise for any inconvenience caused."
The restrictions were lifted after a day of delays and cancellations. Nats said there was “short notice staff absence in the tower”, as well as strong winds in the area.
