ABSTRACT
The main advantage of HMDs is the ability to present information on the pilot’s line of sight (LOS). It is anticipated that HMDs may be used to enable pilots to maintain an awareness of what the aircraft is doing while looking off-boresight, so that they can safely scan and acquire air threats and ground targets. An experiment was conducted to examine the use of HMDs for both these tasks using four different attitude displays: pitch ladder, cylinder, Arc Segmented Attitude Reference and roll-pitch. Novel objective performance measures, designed specifically to evaluate HMD symbology, were collected. Overall, it was found that performance was superior when using the pitch ladder than other displays. This was supported by the subjective findings that the pitch ladder provided higher situational awareness than other displays. It was concluded that the advantage for the pitch ladder may have been due to having the same symbology on the HUD and HMD, enhancing smooth transitioning between the two displays. The implications of this research for future work are considered.
