Virtual reality headsets as external vision displays for helicopter operations - the potential of an exocentric viewpoint

Head-worn displays (HWDs) and aircraft-mounted sensors are common means to support helicopter pilots who operate in degraded visual environment. The use of see-through HWDs is beneficial in brownout and adverse weather conditions because these displays can visualize occluded real world features like the horizon, nearby obstacles, or the desired landing spot. The German Aerospace Center (DLR) investigates an enhanced vision concept called "Virtual Cockpit". Instead of a see-through display, an immersive HWD is used to give helicopter pilots an enhanced out-the-window view. As shown in previous publications, the virtual reality (VR) technology creates benefits for several applications. This contribution explores the advantages and limitations of displaying an exocentric perspective view on the VR glasses. Moving the pilot's eye point out of the cockpit to a viewpoint behind and above the aircraft, appears to be especially useful in situations where the pilot's natural view is degraded by the own aircraft structure. Moreover, it is beneficial for certain maneuvers, in which the real location of the pilot's eye is not optimal for capturing the whole situation. The paper presents results from a simulator study with 8 participants, in which the developed symbology was tested in confined area hover and landing scenarios. The 3D exocentric perspective views increased spatial awareness in the tested scenarios and significantly reduced the required head motion. Further research is needed regarding the attitude awareness with such displays. Apart from helicopter operations, the results may also be relevant for remote piloting solutions and for other types of vehicles with restricted external vision.