This study compared the effect of alternative graphic or numeric vertical navigation(VNAV) aircraft cockpit displays on horizontal and vertical flight technical error (FTE),workload and subjective preference. Displays included: a) a moving map with altituderange arc, b) the same format, supplemented with a push-to-see profile view, including avector flight-path predictor, c) an equivalent numeric display, and d) a numeric non-VNAV display. Sixteen pilots each flew four different approaches with each format in aFrasca 242 simulator. Our VNAV displays reduced vertical FTE by as much as a factor oftwo without increasing workload. Relative advantages of the graphics formats arediscussed.
