AIR TRAFFIC CONTROL: The invisible system between you and the ground

You have flown dozens, perhaps hundreds of times. You have never once seen the system that kept you alive.Every flight you have ever taken was guided, from pushback to gate, by a voice you never heard: an air traffic controller holding a three-dimensional picture of the sky in their mind, keeping your aircraft apart from every other in the most crowded airspace on Earth. Fewer than eleven thousand...