MAXIMUM-MISS AIRCRAFT COLLISION-AVOIDANCE

Aircraft densities in terminal areas increase each year, and the risk of collision grows proportionally. The maintenance of clearance between aircraft in this environment sometimes calls for evasive maneuvers, which depend on the relative position and relative velocity of two aircraft. Small amplitude maneuvers are found for both aircraft in near-miss configurations with short time-to-go. Using low-order dynamics, individual maneuvers are found which maximize the miss-distance. These evasive maneuvers are optimal with respect to the low-order dynamics, and they combine longitudinal (speed) and normal (lift) accelerations. The signs of the accelerations of both aircraft depend on their magnitudes. An evasive climb maneuver, for example, becomes a dive maneuver if the acceleration amplitude exceeds a certain value. The maximum-miss maneuvers appear to have practical potential, because they can be determined on-line from estimated position data for both aircraft.