Safety Separation Assessment in Free Flight Based on Conflict Area

Free flight is an effective way to solve the congestions of air traffic flow. In order to guarantee the flight security, there is great significance to study on collision risk assessment in free flight. This paper applies the idea of collision risk of fixed route based on conflict area for reference, firstly designs a conflict area and establishes the collision risk model in free flight on the basis of it, and then gives the calculation of the parameters in the model. The model considers the influence of communication, navigation and surveillance performance to the probability of overlap and introduces the probability of the failure of controller’s monitoring. The numerical example shows that the model can evaluate the collision risk in free flight effectively.The inverse problem of collision risk model is explored, then the minimum safety separation in free flight is got by simulating, and the advice of reduce the separation is given.