Study of heart rate as the main stress indicator in aircraft pilots

Heart rate is a parameter describing activity of human heart and its psycho-physiological character based on sympathovagal balance of autonomic nervous system, which could be instrumental for indicating stress in aircraft pilots. The assessment focuses on transition from the airplane´s analog presentation of flight data to digital visualization (glass cockpit). The main objective was to examine heart rate of pilots according to the change of flight data imaging during proposed training program, using flight simulator (TRD40 type) and aircraft (DA40 type). Another aim is to interpret stress during different flight tasks and define its influence on pilots´ performance. A group of ten healthy pilots with the same level of experience participated in a seven week training program. A custom designed system consisting of non-complex units was used for measuring procedures during every recorded flight. Heart rate was recorded using a commercial chest belt made by Garmin^®. Spectral analysis of the measured signal has provided the status of sympathovagal balance based on Lomb normalized periodogram. Variation of mental stress according to the values of low to high frequency ratio LF/HF was proven according to the course of training. Results show that the transit from analog to digital visual presentation of avionic data induces stress among pilots and heart rate could be an appropriate parameter defining the actual stress condition.