Psychomotor Alertness and Subjective Fatigue in Helicopter Pilots

Area of Science:

• Aviation Safety
• Human Factors in Aviation
• Aerospace Medicine

Background:

• Fatigue in helicopter operations presents a significant safety risk.
• Subjective fatigue assessments may not align with objective performance deficits.
• Objective measurement tools are crucial for accurate fatigue evaluation.

Purpose of the Study:

• To investigate the relationship between subjective drowsiness and objective alertness in helicopter pilots.
• To assess pilot performance using a psychomotor vigilance task (PVT).
• To determine if self-perceived tiredness correlates with actual performance impairment.

Main Methods:

• An observational field study involving 15 helicopter pilots.
• Subjective sleepiness measured using the Karolinska Sleepiness Scale.
• Objective alertness assessed via pre- and postflight computerized psychomotor vigilance tasks (PVT), measuring reaction time.

Main Results:

• Mean PVT reaction time increased by 11.9% postflight, indicating significant performance decline (Cohen's dz = 0.65).
• A weak association (r = 0.16) was found between subjective sleepiness and postflight reaction time.
• Some pilots with low subjective sleepiness exhibited prolonged reaction times.

Conclusions:

• Objective alertness measures, like PVT, are vital for assessing pilot fatigue.
• Subjective fatigue scales alone may not adequately capture performance impairment.
• Integrating objective and subjective fatigue data can enhance aviation safety and risk management.