Airlift crews were exposed to extended work periods, reduced sleep periods, night work, and circadian dysrhythmia caused by shift work and time-zone crossings during Operations Desert Shield and Desert Storm. This research reveals the extent to which severe subjective fatigue was experienced by the crews during Operation Desert Storm. In addition, through the evaluation of long-term and short-term work and sleep histories, this research shows that recent sleep and flight histories are correlated with high fatigue levels. Furthermore, we found a tendency for fatigue to correspond with pilot error. We recommend that the training of personnel involved in long-duration operations include fatigue management strategies and, further, that work policies and environments be designed to take into account the importance of regular and restorative sleep when unusual duty hours are required.

Brooks Air Force Base, TXThe military goal of Global Reach -Global Power entails an unprecedented dependence on immediate and sustained long range bombing campaigns. This research effort was initiated to evaluate the feasibility of this type of long range operation by studying the effects of multiple long duration missions on bomber &crews. Measures of cognitive performance, mood, fatigue, and sleep management suggest that crews learned to adapt to the missions. However, cognitive performance deteriorated during the early morning hours of each mission and expert ratings of flight deck performance suggest that some components of performance may have been negatively impacted by the repeated missions. This research contributes to the base of information that may be used to make operational risk decisions and suggests ways to reduce schedule-related risks. It also explores the effects of sustained operations on complex tasks, as well as on simple tasks, and explores the use of multiple data collection techniques in a non-laboratory setting.In 1992, the military vision of Global Reach -Global Power was introduced by the Air Combat Command (ACC) division of the United States Air Force ( U S A F ) . This goal entails achieving the ability to launch and perform operations in distant parts of the world from military bases located on the continental United States (CONUS). Achieving this goal would require, among other things, that bomber aircrews be able to repeatedly fly round-trip missions of up to 36 hrs in length. ACC requested that the Sustained Operations Branch of the USAF Armstrong Laboratory (AL/CFTO) investigate the impact of repeated 36-hr missions on B-1B bomber aircrew members. The investigation was designed to uncover issues that should be addressed in order to prepare for the envisioned CONUS-based operations. This paper will focus particularly on effects on aircrew performance. METHOD Eight USAF B-1B bomber aircrews participated. Each crew consisted of four male members: Aircraft Commander (AC), Co-Pilot (CP), Offensive Systems Officer (OSO), and Defensive Systems Officer @SO). Aircrew members were between the ages of 21 and 35. One crew was studied per 12-day period. Materials SubiectsFront and aft B-1B simulators (weapons systems trainers), located side-by-side in a high bay, were linked via an intercom system. Within the front simulator were the AC and CP consoles; within the aft simulator were the DSO and OSO consoles. The simulators were capable of synchronous motion, although this was used only during take-offs, refuelings, bomb runs, and landings. High-fidelity graphics simulated instrument flight conditions during large portions of each mission. Sound and light levels within each simulator were maintained at levels comparable to those experienced in the B-1B during flight. Light levels within the front simulator were adjusted throughout each mission to simulate mission-adapted day-night cycles. Because little ambient light enters the aft section of the B-lB, light exposure in the aft simulator was n...

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.