Proceedings of The Physiological Society

Sleep Sleep and Circadian Rhythms (London, UK) (2018) Proc Physiol Soc 42, C06

Poster Communications

Flying on Empty - The Effects of Sleep Loss on Mood and Task-Specific Competencies in Commercial Airline Pilots

A. O'Hagan1, J. Issartel1, A. Wall1, F. Dunne2, P. Boylan3, M. Herring4, M. Campbell4, G. Warrington4

1. School of Health & Human Performance, Dublin City University, Dublin, Dublin, Ireland. 2. School of Physics, Trinity College Dublin, Dublin, Dublin, Ireland. 3. School of Nursing & Human Sciences, Dublin City University, Dublin, Dublin, Ireland. 4. Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Limerick, Ireland.


Introduction: Current commercial airline flight operations work on a pressurised 24/7 timetable due to the unrelenting escalation in international long-haul, short-haul, regional and overnight flights. As a result, commercial airline pilots are highly suspectible to sleep loss and fatigue. Loss of sleep is proposed to be a key cause of pilot error and could pose a serious threat to flight safety (Caldwell et al., 2009). Therefore, this study examined the effects of 24 hours' sleep loss on mood, pilot-specific competencies and flying performance. Methods: Seven short-haul commercial airline pilots completed the Samn-Perelli Crew Status Check, Profile of Mood States, Psychomotor Vigilance Task, Dual-N-Back, NASA Task Load Index and aviation-specific mathematical calculations. Participants also flew a 32-minute flight profile on a computerised flight simulator during which they were required to answer mid-flight fuel calculations and situational awareness questions. Testing occurred at 3 hour intervals during the final 12 hours of a 24 hour period of continuous wakefulness. Results: One-way repeated measures ANOVA found that feelings of fatigue decreased (F(6, 36)=6.585, p<.001) whilst total mood disturbance increased (†F(1.756, 10.539)=8.734, p<.01) with increasing time awake. Furthermore, sustained attention (†F(1.193, 7.157)=6.491, p<.05), speed and accuracy of problem solving (F(6, 36)=5.897, p<.001; χ2(6)=20.463, p<.01), multi-tasking ability (†F(2.509, 15.055)=3.486, p<.05), perceived workload (F(4, 24)=2.740, p<.05), speed of mid-flight fuel calculations (F(4, 24)=8.561, p<.001) and situational awareness (F(4, 24)=2.923, p<.05) were all significantly impaired following 24 hours continuous wakefulness. Significant reductions in performance were observed on nearly all tests following 20 hours continuous wakefulness. Flying performance was not significantly impacted. Conclusion: Commercial airline pilots' mood and pilot specific competencies were significantly impaired following 24 hours' sleep loss with some impairments becoming evident following 12 hours continuous wakefulness. Whilst most participants were able to maintain flying precision during the period of wakefulness, it appears they are doing so by overcoming large increases in sleep loss and fatigue which considerably degrades cognitive performance. Alas, the number of serious accidents as a result of operator error in various industries due to sleep loss and fatigue is large and appears to be increasing (Lopez et al., 2012) thus warranting further investigation into this area.

Where applicable, experiments conform with Society ethical requirements