Estimation of Conflict Risk Using Cockpit Displays of Traffic Information Technical rept

摘要

This report describes an experiment that evaluated pilots' ability to understand and detect air traffic conflicts on a cockpit display of traffic information (CDTI), without the aid of an automated conflict alerting system. This ability was manifested in estimation accuracy of three continuous variables: miss distance at closest point of approach, time to closest point of approach, and orientation at closest point of approach. Twenty-four licensed pilots viewed a series of dynamic encounters on a 2-D CDTI. The scenarios varied widely in their difficulty, influenced by horizontal conflict geometry (conflict angle, speed, miss distance at closest approach of approach, and distance and time till closest point of approach). Pilots were asked to estimate the point and time of closest approach at varying times before that point was reached. The results indicated that (1) decreased estimation accuracy was associated with conflicts that occurred with slower speeds, a longer time into the future, and a longer distance into the future; (2) a tendency for pilots' judgments often to be conservative, judging that conflicts were both more risky and would occur sooner than was actually the case; and (3) a 'distance-overspeed' bias, such that two aircraft viewed farther apart and converging rapidly were perceived as less risky than two aircraft that were closer and converging slower, even though the time till a conflict occurred was identical. Finally, the cognitive mechanisms that underlie the biases observed in this study are discussed.