Birmingham Airport in England says it has resolved a problem with its air traffic control system that prevented flights from taking off or landing for about two hours.
There was no indication the technical problem in Birmingham on Sunday was related to the drone sightings that caused major problems at London's Gatwick Airport in recent days.
The grounded flights nevertheless caused their share of frustration and worry two days before Christmas. Passengers who had already boarded or reached departure gates were kept in a holding pattern, while some arriving flights were diverted to other airports in England.
Birmingham Airport is located 100 miles (160 kilometers) northwest of London.