Hierarchical Conflict Detection in Air Traffic Control

Abstract
Experienced air traffic controllers and college students participated in 2 experiments we conducted to test a hypothesis that controllers evaluate potential conflicts between aircraft in a hierarchical manner, comparing altitudes first for vertical separation, then extrapolating aircraft trajectories for lateral separation, and finally performing speed-distance computations for longitudinal separation. The results clearly support the hypothesis and imply that controller workload in terms of time pressure could be determined by momentary conflict geometries between aircraft pairs in a sector. Similarity of results between the groups has implications on both our understanding of controller expertise and on experimental research on air traffic control-related issues.