Radar problem caused mayhem in UK skies on Wednesday

Airlines canceled more than 100 flights across the UK on Wednesday after a "technical issue" with radar systems left air traffic controllers flummoxed.

Air traffic in London, Edinburgh, and other UK airports was severely disrupted, the UK's National Air Traffic Services (NATS) warned. Passengers faced long delays while planes queued up to take off from Europe's biggest air traffic hub. A NATS spokesperson told the BBC that the failure was related to radar.

"As a result of a technical issue at NATS Swanwick air traffic control centre, we are limiting the number of aircraft flying in the London control area in order to ensure safety, which is always our first priority," the agency said at the time.

Flight tracking service Flightradar24 said that the entire London control area was closed for a period of time.

A person with working knowledge of the UK's air traffic control system ...