Work of an air traffic controller?  

The work of an air traffic controller consists of directing air traffic with the assistance of a radar display and radio contact with pilots. 

He/she assigns aircraft flight paths and altitudes, and issues take-off and landing clearance. In addition, he/she provides important, up-to-date aeronautical information, required for safe flight operations. Along with the pilot, the air traffic controller is thus the most important active safety factor in aviation.   

Austrian airspace is divided into three control areas, each looked after by a different group of air traffic controllers, so as to ensure that operations are safe and — as far as possible — delays are avoided.  

Aircraft pass in turn from the area for which the tower is responsible to that managed by the approach control and the airspace of the area control centre.  

Tower

The air traffic controllers in the tower give the cockpit crew permission to start the engines, taxi to the runway and take off, traffic conditions permitting, and then provide them with their take-off instructions.

Approach
Once airborne and away from the airport, the pilots need to be guided to the airways. Conversely, when approaching an airport, aircraft need APP’s assistance to find their way from the airway to the instrument landing system. Flight paths often cross, and it is up to APP to ensure that safety is maintained.

The Area Control Center
Austria is blanketed by a network of airways. The air traffic controllers at the area control centre manage all air traffic in Austria’s skies, and ensure that “traffic intersections” in the air are safe to fly across. They must also see to it that all aircraft, however high or fast they are flying, reach their destinations by the shortest possible route and receive clearance to land.
 
by courtesy of Austro Control Gmbh