Physiological and behavioral responses to an exposure of pitch illusion in the simulator

It has been suggested that a pilot's physiological and behavioral responses during disorientation can provide a real-time model of pilot state in order to optimize performance. We investigated whether there were consistent behavioral or physiological "markers" that can be monitored during a single episode of disorientation.

An Integrated Physiological Trainer with a closed loop interactive aircraft control and point of gaze/eye-tracking device was employed. There were 16 subjects proficient in maintaining straight and level flight and with procedures in changing attitude who were exposed to yaw rotation and a brief head roll to 35 +/- 2 degrees. On return to upright head position, subjects were required to initiate either an ascent or descent to a prescribed attitude. BP, HR, skin conductance, eye movements, and point of gaze were monitored throughout the onset, duration, and immediately after the disorientation insult. Simultaneously, airspeed and power settings were recorded.

Compared with the control condition, a significant increase (p < 0.01) in HR, HR variability, and mean arterial BP was observed during the disorientation. Flight performance decrement was reflected by a significant delay in setting power for attitude change and deviation in maintaining airspeed (p < 0.01).

Changes in cardiovascular responses appear to be correlated with the onset of disorientation. The correlation of changing eye-tracking behavior and flight performance decrement is consistent with our previous findings. Further study is required to determine whether these findings can be extrapolated to repeated exposures and to other disorientation scenarios.