Wikipedia
Flyawake
Sustained wakefulness within military combat operations has long been an issue directly related to safety and its impact on those who enter battle. Fatigue remains a formidable enemy in theater operations due to its pervasive impact on cognitive effectiveness during flight. Incidents of fatigue-related errors continue to affect the stability and effectiveness of pilots engaged in 24-7 operations: approximately 20% of all Air Force/ Air National Guard aviation mishaps have fatigue as either a causal or contributing factor.