Contributions of aeromedical research to flight and biomedical science

Pilot and plane capabilities to withstand high-Gz combat maneuvers are tactically important. Sustained 10-15 Gz capabilities of current and future planes outstrip safe physiologic limits in spite of the combined use of World War II-vintage straining maneuvers and relatively ineffective anti-G suits to prevent losses of vision and consciousness. However, the extreme arterial pressure increases needed to maintain cerebral blood flow (e.g. 400 mm Hg at heart level during exposures to 13.5 G when sitting upright) carry risks of anatomic damage to the circulatory system and rupture of air-containing, essentially unprotectable, lungs. These could be minimized, and incapacitating losses of consciousness avoided, by use of horizontal positions designed to eliminate heart-to-head hydrostatic gradients. Development of a prone-position cockpit with a counterweighted, forward-looking head support plus optical-electronically aided all-directional visibility is the most physiologic, safest, and surest way to achieve this goal.