What are common causes of loss of consciousness in flight?

The selection of hypoxia and G-forces as common causes of loss of consciousness in flight is grounded in fundamental principles of aerospace physiology.

Hypoxia occurs when there is a deficiency of oxygen in the air or when the body is unable to utilize oxygen effectively. In flight, particularly at high altitudes, the partial pressure of oxygen decreases, which can lead to reduced oxygen availability for the brain and other vital organs. This lack of oxygen can quickly result in loss of consciousness, a phenomenon known as "altitude sickness."

G-forces, or gravitational forces, become significant in flight during maneuvers such as climbs, descents, and sharp turns. High G-forces can cause a temporary reduction in blood flow to the brain, leading to a condition called "G-induced Loss Of Consciousness" (GLOC). This is especially pertinent during high-performance maneuvers where pilots experience elevated accelerative forces.

In combination, these two factors—hypoxia and G-forces—represent critical physiological challenges that aviators must manage to maintain consciousness and operational effectiveness during flight. Understanding these risks is essential for maintaining flight safety and includes not only awareness of symptoms but also proper training and preventive measures.