Agile aircraft (X-29, X-31, F-18 High Alpha Research Vehicle, & F-16 Multi-Axis Thrust Vector) test pilots, while flying at high angles of attack, experience difficulty predicting their flight path trajectory. To compensate for the loss of this critical element of situational awareness, the X-31 International Test Organization (ITO) installed and evaluated a helmet mounted display (HMD) system into an X-31 aircraft and simulator. Also investigated for incorporation within the HMD system and flight evaluation was another candidate technology for improving situational awareness - three dimensional (3D) audio. This was the first flight test evaluating the coupling of visual and audio cueing for aircrew aiding. The focus of the endeavor, which implemented two visual and audio formats, was to examine the extent visual and audio orientation cueing enhanced situational awareness and improved pilot performance during tactical flying. This paper provides an overview of the X-31 HMVAD system, describes the visual and audio symbology, presents a summary of the pilots' subjective evaluation of the system following its use in simulation and flight test, and outlines the future plans for the X-31 HMVAD system.