Assessing Flight Task Performance of General Aviation Pilots Under Varied Virtual Reality Conditions

An understanding of how pilots complete their flight tasks is an essential element of preventing aviation incidents. Disorientation or a loss of control of the aircraft are some direct causes of such events. This study seeks to assess the impact of environmental factors on the ability of general aviation pilots to complete flight tasks. Certified Pilots (n=16) with experience flying a Cessna 172 or similar aircraft participated. They were tasked with flying a virtual model of a Cessna 172 Skyhawk. This was accomplished using X-Plane 11 flight simulation software, Honeycomb Alpha flight controls, and a Saitek throttle quadrant. The software was integrated with an HTC Vive Pro virtual reality headset. Within X-Plane 11, three environmental conditions were created: Clear, Partial Clouds (Partial Cover), and Full Clouds (Total Cover). All weather conditions other than cloud cover were the same across the environments with no wind present. No clouds are present in the Clear environment. Roughly 50% of the ground is obscured by clouds in the Partial Clouds environment. The ground is completely obscured by clouds in the Full Clouds environment. While in an environment, pilots were tasked with performing a series of 500 ft ascents, 500 ft descents, 90° turns to the right, and 90° turns to the left. These tasks were completed above the cloud layers of the environments. During Day A, the pilots flew in each of the environments twice. During Day B, pilots flew in the Full Clouds environment twice and were exposed to hypoxic air during one of those times. The hypoxic air is 10% oxygen and simulates an altitude of approximately 14,000 ft. The pilots were assessed based on their altitude error, heading error, heading rate of change, task duration, and the amount of motor control effort that was required to complete the task. When flying in environmental conditions that have fewer visual cues such as the Total Cover condition, pilots experienced more error and had to exert more effort to complete the tasks. Visual condition proved to be a statistically significant factor for aileron effort during the altitude tasks (ascents and descents) (p=0.0001, P=1.00), duration of the altitude tasks (p=0.0001, P=1.00), the final heading error of the heading tasks (turns to the right and turns to the left) (p=0.0030, P=0.87), and the duration of the heading tasks (p=0.0001, P=1.00). A trend towards statistical significance of visual condition was observed for the final altitude error of the heading tasks (p=0.0581, P=0.56) and the aileron effort of the heading tasks (p=0.0656, P=0.54). The direction of the task proved to be a significant factor for the final altitude error of the altitude tasks (p=0.019, P=0.65), the aileron effort of the altitude tasks (p=0.0001, P=0.99), the elevator effort of the altitude tasks (p=0.0001, P=0.99), the duration of the altitude tasks (p=0.0001, P=1.00), the final altitude error of the heading tasks (p=0.00297, P=0.84), and the final heading error of the heading tasks (p=0.0001, P=0.99). Exposure to hypoxia resulted in a decrease in performance with an increase in the effort of the pilots. The oxygen condition was significant for the aileron effort during the altitude tasks (p=0.000005, P=0.999) and the aileron effort during the heading tasks (p=0.0135, P=0.71). The direction of the task also proved to be a significant factor for the duration of the altitude tasks (p=0.03315, P=0.573), the absolute altitude error of the heading tasks (p=0.048, P=0.51), the aileron effort of the heading tasks (p=0.0003, P=0.96), and the duration of the heading tasks (p=0.002001, P=0.888). The significance of the task direction reflects the torque of the engine and differences in how the pilots perform certain tasks. The investigation of flight behaviors continues from here with a closer examination of variability of pilot behaviors during tasks. Additionally, the physiological data collected as part of this study still needs to be integrated with the flight data. Finally, the study will be repeated with an active motion platform to investigate the effects of vestibular feedback on pilot performance