Abstract: A plurality of control terminals are arranged to a plurality of control sections. Flight plan data of each control target aircraft is stored in a flight plan data management unit. The present positions of the control target aircraft are checked and acquired by an aircraft position information acquisition unit. The control states of the control target aircraft are managed by a control progress information management unit. The history of control of each control target aircraft is stored in a control progress information storage unit. A control target aircraft prediction unit predicts control target aircraft after a predetermined time on the basis of the control progress information and flight plan information. A control terminal assignment processing unit increases/decreases the number of control terminals on the basis of the prediction result and determines a control terminal for controlling control target aircraft.