Comparison of control and display augmentation for perspective flight-path displays

Manually performed piloting tasks with a perspective flight-path display require considerable effort. To improve this, display augmentation is used: additional symbology such as a flight-path predictor is added. An alternative approach would be to use control augmentation, using fly-by-wire techniques to simplify the control task of the pilot. A control-theoretical analysis of different display and control augmentation concepts is presented. It is shown how design techniques for flight directors can be applied to the analysis of display augmentation. The different concepts have also been tested in a piloted experiment, conducted in a high-fidelity moving-base flight simulator. Experimental results confirm the findings from the control-theoretical analysis. Overall, the control augmentation concepts outperform the display augmentation concepts: Pilot workload and control activity are strongly reduced with equal or better performance. These benefits become more apparent as the task difficulty increases.