What G force is likely responsible for symptoms of head congestion and a lightweight feeling during aircraft control inputs?

The symptoms of head congestion and a lightweight feeling during aircraft control inputs can be primarily attributed to negative G forces. Negative G forces occur when the aircraft experiences a downward acceleration, which can result in blood pooling towards the head. This pooling of blood can create a sensation of head congestion due to increased pressure in the cranial region, as well as the lightweight, buoyant feeling in the body as the forces act in opposition to the normal gravitational pull.

Negative G forces can also lead to a disorientation of bodily sensations, which is compounded by the rapid changes in blood circulation affecting the inner ear, an organ that plays a critical role in balance and spatial orientation. As a result, pilots may feel lightheaded and congested, experiencing these symptoms when subjected to negative G maneuvers, such as during rapid descents or certain acrobatic flight paths where the aircraft pulls out of a dive.

In contrast, positive G forces exert a downward force on the body, potentially leading to G-induced loss of consciousness (GLOC) due to blood being drawn away from the brain. Inertial G refers to forces that are felt when the body moves relative to the aircraft's frame of reference, while gravitational G is the constant force of gravity acting on the