I bring you a weekly bite-sized chunk of the science behind helicopter human factors and CRM in practice, simplifying the complex and distilling a helicopter related study into a summary of less than 500 words.
TITLE:
Effects of Hydration on Cognitive Function of Pilots.
WHAT?
Study examining whether fluid intake and dehydration impact pilots’ cognitive functions (working memory, spatial orientation) and flight performance.
WHEN?
Published in Military Medicine in July 2013.
WHERE?
University of North Dakota, in a simulator.
WHY?
Hydration is critical for sustaining performance, yet helicopter pilots often operate in circumstances and environments where it is challenging to maintain. An improved understanding of how hydration affects cognition and flight safety informs the education of pilots and can lead to improved hydration practices.
HOW?
40 healthy student pilots (aged 18–40) were monitored for fluid intake and hydration levels over a two week period. One group had a controlled high-fluid (≥80 oz/day) and another a low-fluid intake (≤40 oz/day).
Body weight was measured as an indicator of hydration status vs performance measurements for memory, spatial cognition, and flight performance (simulator deviations in heading, altitude, airspeed).
FINDINGS:
- Mild dehydration is defined as 1 to 2% loss of body weight; Moderate dehydration 2 to 5% and severe dehydration more than 5%. The study found that dehydration of 1–3% body weight loss was strongly linked to poorer flight performance (significantly more simulator errors) and reduced spatial cognition scores (situational awareness).
- No significant differences were found between high vs. low fluid intake alone.
SO WHAT?
From a human factors perspective, the findings underscore that:
- Even small levels of dehydration can degrade pilot performance, particularly spatial awareness. Hydration status matters more than fluid intake alone.
- Helicopter crews are especially vulnerable due to factors such as exposure to high cockpit temperatures, lack of onboard facilities, limited toilet break opportunities, and operational demands including long duty cycles (e.g. HEMS, SAR, offshore).
- Performance degradation from dehydration is insidious—pilots may not feel impaired but still make critical errors.
- For flight safety purposes, hydration management should be incorporated into CRM in terms of team awareness and operational risk assessments.
Practical implications include:
- Consider including hydration in fatigue risk management systems and mission planning.
- CRM training should educate helicopter crews to recognise dehydration risks.
- Proactive fluid intake should be encouraged while avoiding diuretics (caffeine and previous consumption of alcohol).
REFERENCE:
Lindseth, P. D., Lindseth, G. N., Petros, T. V., Jensen, W. C., & Caspers, J. (2013). Effects of hydration on cognitive function of pilots. Military Medicine, 178(7), 792–797.
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