ABSTRACT
One of the main problems of modern aviators is to remain awake and alert so that they can diagnose and respond to the remote possibility of an emergency or malfunction. This chapter considers the factors responsible for sleep and mental performance in subjects living normally. It also considers the abnormalities in the air crews' lifestyles produced by their flight schedules. The chapter explains effects of these abnormalities upon sleep and performance in air crew. The rhythm that remains must arise within the body; it is described as an endogenous rhythm, and its generation is attributed to a 'body clock'. The body clock produces daily rhythms in body temperature, plasma hormone concentrations, the outflow of the sympathetic nervous system, and activity in the sleep centers of the brain, all of which exert effects throughout the body. Safety and reducing accidents to a minimum are paramount when the performance of any workforce is concerned.
