How Air Traffic Controllers Operate

Air traffic controllers are responsible for keeping aircraft safely separated from each other. They maintain contact with the aircraft crews through the VHF radio telephone (R/T) service - a vital link in the overall air traffic service. The control of aircraft movements is achieved largely through radar surveillance.

Before an aircraft arrives in a controller’s airspace he is provided with details of the intended flight, including route, altitude, speed and call sign. After taking into account the requirements of another traffic in the sector airspace at that time - or in the future -the controller plans a safe flight level and route for the aircraft and monitors its progress through the sector.

It is a fundamental principle that no aircraft is cleared to enter the airspace of another sector until its entry has been coordinated with an adjacent air traffic control unit. This applies also to the handover of aircraft between national air traffic control and air traffic control services of adjacent countries.

To fly in controlled airspace aircraft must be equipped to a certain standard and their pilots must hold the necessary qualifications. Pilots must obtain a clearance from Air Traffic Control to enter such airspace and, except in an emergency, they must follow ATC instructions implicitly.

In controlled airspace each aircraft must be kept separate from all others by internationally agreed standards. This is done by allocating different heights or by arranging certain minimum horizontal distances between aircraft. These distances vary according to circumstances; for example, two aircraft operating under radar control may not come within five nautical miles of each other at the same height. If two aircraft are less than five nautical miles apart horizontally, they must be vertically separated by a minimum of 1000 ft - or 2000 ft if the aircraft is flying above 29,000 ft.

The responsibilities of an air traffic controller are very high because lives of people depend on his actions. The mistake of a controller may cost very much.

The air traffic controller is responsible for:

a) preventing collisions between aircraft in the air;

b)preventing collisions between aircraft and other obstacles on the ground;

c)maintaining expeditious and orderly flow of air traffic.

The air traffic controller keeps the situation in his sector under constant control. He gives clearances for air traffic, warn pilots about conflicting aircraft. He also informs them about weather conditions, thunderstorm activity, cumulus, visibility and advises avoiding actions. In case of emergency the controller should act quickly and surely and find the only right decision. If necessary he must pass the information to the alerting service.

The controller is also responsible for handover the traffic to adjacent sectors in time. A supervisor is responsible for the work of all controllers subordinate to him.