Carolyn C. Smith
Air traffic control is a system designed to ensure the safe, orderly and prompt flow of commercial, private, and military aircraft through the use of communications, navigational aids, and flight rules.
The primary purpose of air traffic control is to prevent collisions between aircraft while in the air and during takeoff and landing at airports. (See Diagram Below)
(figure available in print form)
The degree of air traffic control exercised by centers, towers, and flight stations depends basically on the weather conditions in which an aircraft is flown. If an aircraft can be flown clear of clouds and the pilot has good visibility, the flight is conducted in accordance with “visual flight rules”. Visual Flight Rules (VFR) flights are subject to little or no control by the ground facilities. The pilots have to make sure they adhere to their assigned altitude. (See Diagram Below) It is the responsibility of the pilot who has been qualified for VFR flight to watch out for the safety of his flight. However, if a flight can’t be conducted in accordance with VFR, it must be conducted under “instrument flight rules” or (IFR). The ground facilities exercise positive separation control over all flights of this nature.
(figure available in print form)
Air Traffic Control is a responsibility of national governments. In the United States, Air Traffic Control is assigned to the Federal Aviation Administration (FAA). The FAA is an agency of the Department of Transportation. In Canada, the Air Transportation Administration provides this service.
Airplanes travel highways in the sky. They obey traffic signals and follow traffic laws much as automobiles do. Air Traffic Control might not seem necessary since the sky extends from horizon to horizon and up to outer space. In bad weather, however, airplanes that are allowed to fly at any altitude or along any course might collide. Even in good weather, the many planes landing at an airport might cause a traffic jam.
Air Traffic Control is necessary to make flying safe as well as to avoid delays. The regulation of airplanes along airways, or air routes between airports is called air-route traffic control. Controlled air space at an airport is called a control zone.
