Sleep and Flight Duration Effects on the Subjective Fatigue of Pilots during Operation Desert Storm

Abstract

Subjective fatigue of 11 C-141 pilots serving in the United States Air Force Military Airlift Command (MAC) during the Desert Storm campaign was assessed in a 30-day field study. Subjective fatigue measures were obtained from pilots at the beginning and end of each duty day using the Profile of Mood States (POMS) fatigue dimension. Also, a 7-point fatigue rating was recorded every 4 hours. The two fatigue measures were each evaluated with respect to (1) 48-hr cumulative flight time, (2) 48-hr cumulative sleep time and (3) 30-day cumulative flight time. The data indicate that at least 15 hours of sleep per 48-hr time period is needed to avoid pilot fatigue. Recent flight time was also found to be related to subjective fatigue, but this relationship seems rooted loss of sleep during long flights. Cumulative 30-day flight time, which is the measure currently used to regulate flight hours, was not related to increases in subjective fatigue.