Cybersickness remains a significant impediment to the widespread adoption of extended reality (XR) in flight simulation. This study aims to assess the potential of mixed reality (MR), a hybrid approach that merges physical cockpit elements with virtual environments, to alleviate cybersickness compared to virtual reality (VR) setups within helicopter flight simulation. Seven licensed helicopter pilots flew during two conditions, MR and VR, a predefined 20-minute track with a set of flight manoeuvres. For the experiment, pilots operated a fixed-base helicopter pilot station that features a cockpit mock-up. For both conditions, the JVC HMD-VS1W, an optical see-through head mounted display (HMD) featuring additional downward facing windows, was utilized. During the VR condition, the HMD semi-transparent display and the downward-facing windows were covered so that only the virtual environment was visible. During the MR condition, the HMD was optimally utilized by digitally masking the virtual environment at the locations where the physical cockpit elements were present. Additionally, the downward-facing windows allowed only real-world elements to be visible, possibly providing a greater sense of field of view and increased body awareness. A combination of subjective measures, including simulator sickness questionnaires and the Misery Scale, and objective measures, including electrodermal activity and postural stability were collected to identify cybersickness. Moreover, the 6-degrees-of-freedom head position was tracked to identify head movement differences between conditions. Results indicate similar increases in cybersickness and electrodermal activity across conditions. Surprisingly, both conditions led to a slight improvement in postural stability, without significant differences between conditions. Despite equal virtual environment exposure, VR resulted in increased head movement, possibly due to inhibited field-of-view perception from downward-facing windows relative to the MR condition. These findings underscore that the ability of this type of optical see-through MR to alleviate cybersickness is negligible compared to conventional VR setups.

Keywords
AUGMENTED AND VIRTUAL REALITY (AR/VR);FLIGHT SIMULATION;FLIGHT TRAINING;MIXED REALITY;MOTION;SIMULATORS

Additional Keywords
Cybersickness, training effectiveness, helicopter flight simulation