Definition
A sudden loss of consciousness caused by high positive G-forces during flight maneuvers. When the aircraft pulls hard Gs, blood is forced away from the brain toward the lower body, depriving the brain of oxygen. If the pilot does not counter this with proper anti-G straining techniques or G-suit support, vision narrows, then fades, and consciousness is lost — often without warning.
Plain English
Passing out in flight because hard maneuvers push too much blood out of your head. Your brain runs short of oxygen and you black out, sometimes with no time to react.
Context Anchor
Seen in discussions of aerobatics, high-performance aircraft, steep pull-ups, and any maneuver that can create high G forces.
Derivation
G refers to the force of gravity. One G is the normal pull you feel standing on the ground. Higher G-loads multiply that force, and 'G-induced' simply means caused by those forces.
Why Pilots Care
Unconsciousness removes the pilot from aircraft control and can lead to loss of the aircraft or collision with terrain.
Grounding Statement
In a hard pull, the pilot’s body can feel much heavier, and blood can be forced toward the lower body instead of staying in the head.
Intuition Check
G-induced loss of consciousness is not simply fainting from fear or stress. It is a physical effect caused by acceleration forces reducing blood flow to the brain.
Example Sentence 1
The fighter pilot tightened his abdominal muscles during the high-G turn to avoid G-induced loss of consciousness.
Example Sentence 2
Centrifuge training exposes pilots to the onset of G-induced loss of consciousness so they recognize the warning signs early.