GLIDING HIGH: PLEASURE OR PAIN

Abstract

Gliding has become an increasingly popular recreational and competitive pastime, with some 1100 glider pilots registered in New Zealand, and 91 competitors at the 24th World Gliding Championships in New Zealand in 1995. Most scientific activity concerned with the sport of gliding has centered on aerodynamic designs, more sophisticated meteorology, and so on; research whose aim is primarily to enhance the interactive performance of man and machine. But, the glider pilot faces another, somewhat insidious, hazard - namely, hypoxia (or, lack of oxygen). Humans are very susceptible to an oxygen deficiency and unprotected exposure to altitude (such as that experienced by aviators, mountaineers, etc) is one of its principle causes. Current New Zealand Civil Aviation Regulations permit crews of unpressurized aircraft, such as gliders, to fly below 10,000ft (3,048m), and to fly between 10,000 and 13,000ft (3,048 and 3,960m) for up to 30 minutes, without supplementary oxygen. The effect of breathing air at these altitudes causes hypoxic hypoxia, a reduction in the oxygen tension in the arterial blood and hence in the tissues.