What does negative Gz force indicate?

Negative Gz force refers to the force experienced when an aircraft or any object undergoes rapid descent or sudden vertical acceleration downward. In this context, negative Gz means that the force is acting in the direction from the feet towards the head of the individual.

When a pilot experiences negative Gz forces, the physiological effects can include increased pressure on the head and a sensation of weightlessness in the lower body. This is contrary to positive Gz forces, which push down from the head to the feet, resulting in increased gravitational effects on the pilot's body. Understanding negative Gz is crucial in aerospace physiology as it relates to the potential physiological impacts on the body during maneuvers or activities in an aircraft, including the risk of loss of consciousness due to blood pooling in the lower extremities. This physiological understanding is vital for safe operation and training of pilots in various flight scenarios.