Decision and Workload Implications of Free Flight and the Cockpit Display of Traffic Information (Cdti)

Abstract

Twenty-two certified flight instructors flew a general aviation simulator, either actively selecting and flying maneuvers to avoid traffic conflict, using a cockpit display of traffic information (CDTI) in a free flight scenario, or more passively executing corresponding maneuvers as commanded by a simulated air traffic controller, in a conventional scenario. The maneuvers spontaneously chosen by the pilots in the freeflight scenario were found to be only partially consistent with the maneuvers for traffic avoidance, dictated by current FAA “rules of the road”, with pilots showing a marked preference for making vertical rather than lateral maneuvers, and climbing rather than descending maneuvers. Pilots also preferred to make simpler single axis maneuvers. Visual scanning in both scenarios was measured, revealing that pilots spent a majority of their time fixating on the instrument panel, and in free flight, they distributed their remaining visual attention differentially across the two sources of traffic information, the outside world and the CDTI. In all conditions, they were particularly vulnerable to missing the detection of traffic which was not annunciated on the CDTI, but was visible on the forward view.