AIR TRAFFIC CONTROL (ATC) -- There is always a control tower in every international airport worldwide. Do you know that Air Traffic Controllers are also known as the pilot's pilot? They guide, monitor (by radar & radio) and instruct all airborne pilots on every flight info and procedures there are to ensure safe air transportation 24 hours, 7 days a week! They designate and assign given air lanes to each individual flying aircraft inbound or outbound to avoid aircraft collision on what they call the highways of the skies. You would think that because of the vast expanse of the sky planes can fly anyway they want to. No siree! Actually there is traffic in the skies. Planes can only change their altitudes or divert direction only when cleared by ATC. Planes cannot take off unless the skies are cleared of incoming aircraft. Neither can they land unless the runway is cleared. My hats off to all you ATC's!