ABSTRACT
Today’s flight operations work on pressurised 24/7 timetables. As a result, sleep loss and fatigue are becoming commonplace among pilots and pose a serious threat to flight safety. This study examined the effects of 24 h’ sleep deprivation on a variety of psychological measures, cognitive performance tasks and simulated flight. Seven commercial airline pilots completed the Samn-Perelli Crew Status Check (SPC), Profile of Mood States (POMS), Psychomotor Vigilance Task (PVT), Dual-N-Back, Rapid Visual Information Processing Task (RVP), NASA Task Load Index (NASA-TLX) and aviation-specific mathematical calculations as well as a computerised flight simulator task, during which participants were required to answer mid-flight fuel calculations and situational awareness questions (SA). Testing occurred at 3 hour intervals during the final 12 hours of a 24 hour period of continuous wakefulness. Significant impairments in performance were observed on nearly all tests following 20 hours continuous wakefulness. Flying performance was not significantly impaired. Changes in flight performance were found to be consistent with changes in situational awareness. Overall findings showed impairments in mood, cognition and flying performance following 20 hours continuous wakefulness. SA indicates promise as a potential indicator of changes in flying performance as a result of sleep deprivation and fatigue.
Acronyms
FP | = | Overall composite flight performance deviation (from the green line); |
AH | = | Auditory hits (on the dual-n-back task); |
AIRSIM | = | Avionics integration research SIMulator; |
APM | = | Average pitch magnitude; |
ARM | = | Average roll magnitude; |
ATM | = | Average throttle magnitude; |
CR-FC | = | Number of correct responses on the mid-flight fuel calculations; |
CR-MC | = | Number of correct responses on the mathematical calculations; |
HDEV | = | Horizontal deviation from the green line |
NASA-TLX | = | National aeronautics and space administration-task load index; |
POMS | = | Profile of Mood States; |
PVT | = | Vigilance task; |
PVT-MLA | = | Psychomotor vigilance task-mean lapses in attention; |
PVT-MRT | = | Psychomotor vigilance task-mean reaction time; |
RVP | = | Rapid visual information processing task;. |
SA | = | Situational Awareness; |
SPC | = | Samn-perelli crew status check; |
TAS | = | Total airspeed;. |
TMD | = | Total mood disturbance; |
TT-FC | = | Time taken on the mid-flight fuel calculations; |
TT-MC | = | Time taken on the mathematical calculations; |
VDEV | = | Vertical deviation from the green line; |
VH | = | Visual hits (on the dual-n-back task) |
Acknowledgments
The authors would like to sincerely thank all those who were involved in the development and running of this study. Special thanks are needed for the National Aerospace Laboratory (NLR) in Amsterdam for use of their computerised flight simulator software (AIRSIM) and also to Jeppessen for access to their navigational air charts for use in the AIRSIM. And finally, a huge thanks to all those participating in this study.
Disclosure statement
No potential conflict of interest was reported by the authors.
Notes
1. Due to potential violations of non-normality as a result of a small sample size, Friedman tests were run. Friedman Findings: POMS-Confusion, χ2(6) = 15.904, p < .05; POMS-Vigour, χ2(6) = 25.564, p < .001; Total Mood Disturbance, χ2(6) = 27.572, p < .001; Samn-Perelli Crew Status Check, χ2(6) = 21.868, p < .01; PVT-Minor Lapses in Attention, χ2(6) = 25.852, p < .001; PVT-Mean Reaction Time, χ2(6) = 29.878, p < .001; Multi-Tasking Ability, χ2(6) = 9.810, p = .133; Visual Hits, χ2(6) = 9.079, p = .169; Auditory Hits, χ2(6) = 7.441, p = .282; RVP-Correct Rejections, χ2(6) = 20.406, p < .01; RVP-Misses, χ2(6) = 23.207, p < .01; Time Taken for aviation-specific mathematical calculations, χ2(6) = 20.082, p < .01; Situational Awareness, χ2(4) = 11.496, p < .05; Time Taken for mid-flight fuel calculations, χ2(4) = 11.543, p < .05.