+Gz Acceleration Loss of Consciousness: Time Course of Performance Deficits with Repeated Experience

Abstract

Pilots of modern fighter aircraft encounter episodes of gravity-induced loss of consciousness (GLOC) consisting of complete unconsciousness and subsequent confusion. According to Whinnery, Burton, Boll, and Eddy (1987), pilots are totally incapacitated for 24 sec during such episodes. Using centrifuge simulators to induce GLOC and math and tracking tasks to emulate flight performance, this study confirms the duration of total incapacitation described by Whinnery et al. (1987) and also indicates that the GLOC problem is more serious than they envisioned. Performance efficiency deteriorates from 3.20 to 7.44 sec prior to the onset of unconsciousness and does not return to baseline levels until 55.5 sec after the confusion phase has ended. Thus, at speeds of 500 mph typical of modern fighters, pilots can travel 12.1 miles while not in control of their aircraft. These effects do not appear to be reduced by repeated encounters with GLOC.

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