A Method to Calculate the Collision Risk on Air-Route

In order to improve the airspace transportation service and management capabilities, the airspace planning is very effective measure. The evaluation of safety is an important step in the design of air-route and is a key element in the specification of separation standards. In this paper, Collision risk model of air-route based on the variable nominal separation is given. In contrast to the most existing route collision risk models that are suitable for the invariable nominal separation between two aircraft, the collision risk model of variable nominal separation between two aircraft that are flying with different speed is researched. The expression of collision probability of the two aircraft at the any time on the air-route is given and then the number of fatal accidents per flight hour is given. The results show that the model characterizes the collision risk well based on the variable normal separation and the number of fatal accidents per flight hour of any flight segment can be calculated. These will provide the method and theory to research the safety and management in airspace.