+Gz-induced loss of consciousness: a case for training exposure to unconsciousness.

+Gz-induced loss of consciousness (G-LOC) continues to be a threat to aircrew flying high-performance fighter aircraft. All avenues to prevent G-LOC, and to reduce the resulting incapacitation should G-LOC occur, must be explored. Research has begun to accurately quantify all aspects of the G-LOC phenomenon. The emerging pattern from this research indicates that, theoretically, G-LOC incapacitation could be significantly reduced. Comparison of G-LOC with LOC induced by acute arrest of cerebral circulation reveals that the G-LOC incapacitation could be reduced by as much as 17 s. Results also indicate that the relative incapacitation period (confusion and disorientation) following unconsciousness could be reduced by at least 9 s for an individual who has previously experienced G-LOC. This suggests that exposure to G-LOC during centrifuge training could provide this orientation to G-LOC and potentially reduce the incapacitation period should it occur inflight. This exposure may be likened to the current altitude-hypoxia training requirement for aircrew. Experience to date supports the contention that such training may be accomplished with an acceptable safety margin.