General component is air traffic control program control and radar put under surveillance. At present unit of our country major air traffic control still uses backward program control, guangzhou area is active is interpose at both the program control below the radar monitoring condition between. Radar put under surveillance (RADAR CONTROL) it is to show information of direct use radar will provide service of air traffic control.
Interval of the smallest level is different between the aerostat that the distinction with program control and radar the clearest put under surveillance depends on method of two kinds of control allowing. Inside area control limits, program control requirement is the same as height with course the smallest level is removed between aerostat 10 minutes (to large and medium-sized for the plane, the distance that is equivalent to 150KM left and right sides) , the program control interval below radar monitoring condition needs 75KM only, and interval of radar put under surveillance needs 20KM merely.
Permission the smallest interval is smaller, thinking the effective utilization rate of unit airspace is older, flight sortie size is larger, direct of the air route in be helpful for keeping empty more is smooth, more be helpful for raising flight safety factor and airliner to be led normally.
The country that foreign air traffic control develops had realized radar put under surveillance in the round, and Chinese civil aviaton is in Beijing, Zhuhai to wait for airspace of little scope, low altitude to carry out radar put under surveillance into close control only at present.