A air traffic controller.
to control air traffic
Neither - an air traffic controller is a person, not hardware or software. They are responsible for air traffic flow.
you are a madman
air traffic controller
The the AIr traffic Controller (Tower) giving the pilot the permission to land as the runway is clear for them
"Air Traffic Controller" "Advanced transfer cache"
Air Traffic Controller
you cant
Leslie Vernon Smith.
Any controller that covers that particular airport, or if they are VFR "Flight Following", whatever radar controller that covers that area. In other words, helicopters are controlled by the same Air Traffic Controllers as normal traffic.
James A. Mathews has written: 'How to prepare for the air traffic controller exam' -- subject(s): Examinations, questions, Air traffic control, Air traffic controllers