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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.