Description

When executing rapid flight control inputs to effect changes in the trajectory of an aircraft certified for aerobatic manoeuvres, the pilot may be vulnerable to G-induced impairment which can culminate in G-induced Loss of Consciousness (G-LOC). The effects are a result of the inertial forces created during such manoeuvres and the vulnerability to their physiological consequences which has been shown to vary widely amongst individuals.

Different types of G

Whilst positive or negative acceleration in all three axes of the human body can produce acceleration against gravity, the G-force which of is of the most potential concern in respect of aircraft control, and which is the concern of this article, is the gravitational force which occurs along the vertical or ‘z’ axis of the body in the positive (head to foot) direction. Such acceleration is referred to as +Gz to distinguish it from acceleration in the opposite negative direction (-Gz) and from lateral (shoulder to shoulder) acceleration (Gy) and fore-aft (front to back or back to front) acceleration (Gx).