A 98 - 37086 Aiaa - 98 - 4242 Evaluation of Vertical Collision Avoidance Maneuvers for Parallel Approach

Two candidate evasion maneuvers were evaluated for use with a collision alerting system for independent closelyspaced parallel approaches in instrument conditions. The two maneuvers were a wings-level climb and a climbing turn away from parallel traffic. .Pairs of aircraft on parallel approach were simulated using pre-recorded trajectories covering a range of normal approach and blunder scenarios. Each scenario was repeated twice, with the endangered aircraft responding to alerts with either the climb-only or the climbing-turn evasion. The climb-only maneuver is shown to result in 38-times as many collisions as the climbing-turn for nominal alert threshold settings. It is possible to reduce the collision rate by adjusting threshold parameters, but the false alarm rate increases. The climb-only maneuver is shown to be uniformly less safe than the climbing-turn for all parameter combinations. Results are illustrated using System Operating Characteristic curves.