Strategic Conflict Resolution Methods of Aircraft

Abstract

This paper describes strategic conflict resolution methods of aircraft, in particular, a resolution where initiation time is approximately between 8 and 20 min before the closest point of approach and where resolution cost and safety are important factors. A course change resolution, a speed change resolution, and a combination of the two are discussed. An equation for a required course change angle and a required speed change is derived from the speeds of both aircraft, the path crossing angle, the minimum predicted separation, the required resolution distance and the resolution initiation time. In order to compare the cost of the resolution methods, a cost estimation function based on the time delay is defined.

Numerical examples are given to illustrate the characteristics of both resolution methods. The resolution strategy depends on the path crossing angle and the resolution initiation time. In these examples, it is found out that a course change resolution is effective for aircraft pairs with large path crossing angles or near head-on conflicts, while a speed change resolution is effective for aircraft pairs with small path crossing angles. A chart that shows resolution decision as a function of the path crossing angle and the resolution initiation time is used to select the resolution method. A cooperative resolution method, where both aircraft participate in, is also described.