The Link Between Spatial Disorientation in Flight and Mild Hypoxia.

Spatial disorientation is a collection of symptoms that signal the brain’s inability to coordinate the position or movement of the person relative to the earth’s surface. It is particularly dangerous for aviators, astronauts, and divers. For example, spatial disorientation events in flight are usually 90% fatal for the pilot, and many events labeled pilot error may have been errors induced by spatial disorientation. Hypoxia is a state of oxygen deficiency in the tissues of the body sufficient to cause impairment of function. The brain consumes more O2 relative to its size than any other tissue, so small O2 reductions would be expected to have large effects on neural tissue. The FAA requires supplemental O2 must be used at altitudes above 15000 feet due to the dangers of cognitive effects from hypoxia. However, there is sufficient evidence from mountain climbers and other sources that dangerous impairment of neuro vestibular functions occurs at thousands of feet below this supplemental O2 altitude. We propose that pilot error or hypoxia events may actually be incidents of spatial disorientation induced by mild hypoxia. In a preliminary study, we found significant effects on disorientation scores at 12000 feet simulated altitude. Since the effects are most pronounced during exposure to gravitoinertial forces of flight, we use the Coriolis illusion in a Barany chair to test these effects. If successful, the results will be used to attract funding for a more extensive study; hopefully that uses actual flight conditions and disorientation