A requisite condition for following up the aircraft is the accurate assessment of the aircraft range and its closing speed to a ground-based radar. The relevant point is to simulate the change of the aircraft position and its closing speed relative to the radar, corresponding to the real processes to ensure its accurate and stable tracking. Different situations of cargo aircraft flight along the curvilinear trajectory segment (racetrack turns-in) and flight along the straight-line segment of the racetrack are considered. The values of model parameters for the cases of maneuver and non-maneuver, determined on the basis of the research results, are presented. Each of the states is defined by specific values of the model parameters and the law of the forming noise distribution.