Crew fatigue during simulated, long duration B-1B bomber missions

Area of Science:

• Aerospace Medicine
• Human Factors Engineering
• Sleep Science

Background:

• Long-duration missions pose significant challenges to crew performance and safety.
• Understanding crew fatigue is critical for optimizing operational effectiveness in aviation and space exploration.
• Previous research has highlighted the impact of extended duty periods on physiological and psychological states.

Purpose of the Study:

• To evaluate crew fatigue during successive, unaugmented 36-hour missions in a B-1B simulator.
• To investigate the physiological and subjective responses to prolonged operational demands.
• To identify the most challenging mission phases and contributing factors to fatigue.

Main Methods:

• Utilized B-1B simulators for a controlled study involving 32 operationally qualified crewmembers.
• Monitored physiological markers including oral temperature, salivary melatonin, and cortisol levels.
• Employed actigraphy and subjective questionnaires to assess sleep quality, duration, and perceived fatigue.

Main Results:

• Crewmembers maintained their circadian rhythms despite mission demands, as indicated by temperature and melatonin data.
• The initial mission presented the highest levels of perceived fatigue and cortisol, suggesting it was the most demanding.
• Sleep quality and duration were significantly reduced during the first mission compared to subsequent missions.

Conclusions:

• The first long-duration mission is the most taxing for crews, necessitating specific adaptation and management strategies.
• Maintaining circadian alignment does not fully mitigate fatigue and performance decrements in extended missions.
• Realistic fatigue management training is essential to improve crew safety and effectiveness throughout successive long-duration missions.