Medical evaluation of G-sensitive aircrewmen

Etiologies for loss of consciousness in an aerospace environment are diverse and may present as a perplexing problem in specific cases. The high, sustained G that current aircraft are capable of producing represent another etiology for inflight loss of consciousness. Protective measures give only partial protection, however, and pilots continue to remain susceptible to the excessively high G forces. Certain protective methods, including M-1 and L-1 straining maneuvers, may actually become a source of loss of consciousness if not performed correctly. The current methods utilized to evaluate loss of consciousness in flight, as demonstrated in the specific case of a student pilot performing an improper straining maneuver, are reviewed. Specific measures that might be instituted to prevent certain of these loss-of-consciousness episodes are recommended. The human centrifuge can be an integral part of aeromedical evaluation when G-related problems are involved and is an extremely valuable training device in determining individual G tolerance and enabling controlled G-stress training. Use of the centrifuge in high-G training could well lead to both human life and aircraft cost savings in addition to assuring full utilization of today's high-performance aircraft.