Field of View Effects on a Simulated Flight Task with Head-Down and Head-Up Sensor Imagery Displays

Abstract

When pilots fly an aircraft with sensor imagery rather than direct vision, their instantaneous field of view (FOV) is restricted severely. This limitation has been identified as a major human factors problem in aviation and has fostered efforts to develop displays with much wider FOVs than are currently available. Two experiments are reported investigating FOV effects in simulated flights with sensor imagery appearing on a Head-Down Display (HDD) and a Head-Up Display (HUD). The outside world was viewed via a simulated sensor image with a 25, 40, or 55 deg FOV, while the surrounding world was dark and provided no additional information. The subjects' task was to fly a slalom course without hitting the pylons or missing the intervals between pylons. The results indicate significant effects of FOV on both hits and misses for both the HDD and the HUD. In addition, performance was significantly affected by the speed of flying and the level of training. With the narrow FOV, subjects flew closer to the pylons than with the wide FOV and hit the pylons more often. These results are interpreted as an indication that subjects perceived the sensor display as the entire world rather than as a window into the world. This effect was somewhat smaller with the HUD than with the HDD, possibly because the HUD better represented a window into the world. The differences between the HUD and the HDD, however, did not reach statistical significance.