Shower thought of the day



OT Supporter
Jan 13, 2005
Chattanooga, TN
What if we find someone who handles negative G’s and he could pull some crazy shit, but nobody ever built a plane for him...0


Well-Known Member
Mar 24, 2016
The house that hate built.


OT Supporter
Jan 13, 2005
Chattanooga, TN

Under normal conditions, your body must maintain 22mm of mercury blood pressure to get blood from your heart to your brain. Each additional +Gz (blood flows from the head to the feet) that a person experiences multiplies that requirement: The body has to muster double that at 2g, triple that at 3g, and so on until they hit around 4 or 5 G’s, at which point most folks will pass out due to oxygen starvation because all the blood stays in their feet.

This condition is known as G-LOC (G-induced loss of consciousness). Fighter pilots, with the aid of flight suits packed with air bladders that force blood out of the lower extremities as well as specialised breathing and tension techniques, can be trained to withstand up to 9 +Gz.

Per the Federal Aviation Administration, the +Gz effects include:

(1) Grayout. There is graying of vision caused by diminished flow of blood to the eyes. Although there is no associated physical impairment, this condition should serve as a warning of a significant impairment of blood flow to the head.
(2) Blackout. Vision is completely lost. This condition results when the oxygen supply to the light sensitive retinal cells is severely reduced. Contrary to other common usages of the term, consciousness is maintained. In blackout, some mental activity and muscle function remains, thus the occurrence of blackout warns of seriously reduced blood flow to the head and of a high risk of loss of consciousness. Note: In some centrifuge studies, 50 per cent of the pilots had simultaneous blackout and loss of consciousness. Therefore, a pilot cannot rely on blackout to precede loss of consciousness.
(3) Loss of Consciousness. When the blood flow through the brain is reduced to a certain level, the pilot will lose consciousness. He or she may have jerking, convulsive movements; these have been seen in many subjects of centrifuge studies and in some pilots during actual flight. The pilot will slump in his or her seat. Possibly, the pilot will fall against the controls, causing the aircraft to enter flight configurations from which it cannot recover even if consciousness is regained. In centrifuge studies, many pilots lost (and regained) consciousness without realising they had done so.

Negative Gz-forces, however, are an entirely different matter. Nobody, literally no human — anti-g suit or not — can withstand more than 2 or 3 negative Gs before losing consciousness due to all the blood in their body pooling in their head. As the FAA continues:

b. Negative Gz Effects. Negative Gz is encountered when acceleration is in a foot to head direction, such as might be obtained during inverted flight, or during an outside loop or pushover manoeuvre (see Figure 2). Blood is then pushed toward the head, and the amount of blood returning from the head is diminished, so the blood tends to stagnate, particularly in the head. Under mild conditions of -Gz forces, the pilot will feel congestion, as when standing on his or her head. Engorgement of blood vessels causes a reddening or flushing of the facial skin. Blood vessels in the eyes will become dilated. Some persons may experience a headache. A condition termed “redout” may occur. This may be due in part to congestion but may also occur when the lower eyelid, reacting to -Gz, rises to cover the pupil, so that one sees light through the eyelid.

So rocket assisted skydiving is out of the question?

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