LONDON, July 30 (Reuters) - A radar-related technical issue in Britain's air traffic control system disrupted flights for over four hours at major airports in London and elsewhere on Wednesday, though the issue was later resolved and departures were resuming.

The federal government runs air traffic control because that was the easiest way to do things in the early days of flying. Today, the entire system remains federally managed—even as commercial aviation has become far more complex.