INFLUENCE OF SLEEPINESS ON PILOT PERFORMANCE IN THE FLIGHT SIMULATOR

Abstract

Introduction: Fatigue and sleepiness is a well studied factor that reduces performance in dynamic working environments like aviation. Epworth Sleepiness Scale (ESS) is a user friendly and standardized way of measuring sleepiness. The aim of this study was to correlate sleepiness and fatigue indicators with pilot performance measures during a flight simulator exercise. Method: 54 trainee pilots answered questions regarding subjective and objective sleepiness indicators (amount of hours slept, subjective sense of sleepiness, ESS). They were then asked to fly a demanding mission in the flight simulator, which included and instrument approach to the airport. A calculation of performance measures was followed (deviation of the real glide path from the ideal one, number of crossings between them and the overall trainee grade) Sleepiness markers and performance measures were correlated using regression analysis and Student’s t-test. A level of significance of 95% was used. Results: A significant correlation (p=0.0003) between ESS-measured sleepiness and the mean deviation between the performed and ideal glide path was found.
The time of the day (morning-afternoon) the task was performed and the overall mark by the instructor were also correlated. The effect of sleepiness on performance is a serious yet predictable factor that can relatively easily be measured. For the first time in this study we showed that even small levels of sleepiness in the setting of every day activities can affect pilot performance.