Analyzing pilots’ fatigue for prolonged flight missions: Multimodal analysis approach using vigilance test and eye tracking

Performance decrement associated with pilot fatigue is considered a leading contributor to aviation accidents and fatalities. The output of prevalent pilot fatigue methodologies (both subjective & objective) either suffer from human judgement bias or require complex data processing. Moreover, studies catering to long duration flight missions have not been performed. Presently, we investigate the impact of fatigue on pilot performance for long duration of a flight mission composed of multiple take-offs and landings. We propose a new multimodal approach that integrates traditional fatigue metrics with eye tracking methodology. The effect of fatigue on the pilots’ eye movements was evaluated using information theory-based entropy measures. Results showed an increase in the fatigue level (measured by mean reaction times and the number of lapses) with increase in flight duration. The entropy measures showed that visual attention distribution and scanning strategy both became random in nature as fatigue level increased in pilots. Obtained results suggest fatigue decreases both information searching and processing capability in pilots. The proposed method can show which aspect of the pilot performance becomes impaired by fatigue and thus can be applied to evaluate fatigue onset in real time, which enables timely recovery interventions.