A Comparison of Helmet-Mounted Display Symbologies During Live Flight Operational Tasks

Spatial disorientation continues to be one of the most costly problems in military aviation, as measured by both life and equipment loss. The unique Helmet-Mounted Display (HMD) centric interface within 5 th generation aircraft has the potential to increase tactical capabilitywhen compared toprevious similar-role aircraft.This study investigated the addition of off-axis ownship attitude information within the HMD field-of-view when the operator looksaway from the virtual Head-Up Display (vHUD). In some 5 th generation aircraft, traditional HUD symbology is presented via the HMD as there is no aircraft-fixed combiner. In some instances, the only attitude information included via the HMD is part of the vHUDsymbology and is only available when the operator looks forward. For this study, a comparison was performed between a baseline representativesymbology design and two other interfaces which included variations of off-boresight attitude information symbology. Air-to-groundtactical tasks of varying complexity were performed in live flight by evaluation pilots seated in the rear cockpit of an L-29 aircraft while donning a5 th generation representativeHMD system. In addition to the HMD symbology, the visual scene presented was a virtual depiction of a mountainous terrain area. The real outside world was occluded by an opaque hood affixed to the canopy glass. Qualified pilots (n = 10) participated in the study and each flew three approximately one-hour flights. Data collection included quantitative performance, physiological response, and subjective feedback, and preliminary results are presented here