Student Drowsiness During Simulated Solo Flight

INTRODUCTION: Pilot fatigue is a significant concern in aviation, where efforts are directed at improving rosters, developing models, and improving countermeasures. Little attention has been given to in-flight detection of fatigue/drowsiness. The aims of this research were to determine whether drowsiness is an issue and explore whether infrared reflectance oculography could prove useful for continuous inflight monitoring. METHODS: Nine university-based pilot trainees wore activity monitors and completed diaries, prior to a simulated navigational exercise of approximately 4 h, during the secondary window of circadian low. During the flight they wore a head-mounted device. Oculographic data were collected and converted into a single number, using the Johns Drowsiness Scale (JDS), with increasing values indicating greater drowsiness (range 0.0 to 10.0). RESULTS: Peak JDS values reached 6.5. Values declined from shortly before top of descent, continuing until landing. Two of the nine participants (22.2%), reached drowsiness levels at or above a cautionary warning level, below which is considered safe for driving a motor vehicle. DISCUSSION: The results of this study revealed the timeline and levels of fatigue that might be experienced by student pilots; showing that drowsiness is a potential issue for student pilots operating in flying conditions similar to those in the simulation. Analysis indicated that pilots are likely to experience levels of drowsiness above a cautionary warning level when modeling predicted effectiveness below 90%, indicating a potential drowsiness issue for pilots. It was concluded that oculography is worthy of further investigation for use as an objective fatigue detection tool in aviation.