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A g-suit is worn by aviators and astronauts subject to high levels of acceleration in order to prevent loss of consciousness, commonly called blackout or g-LOC, g-induced loss of consciousness. Various shapes and sizes of g-suit have been developed, but all current and past designs use compressed air to make the suit exert force on the lower body and legs during flight and flight manoeuvring subject to high g-force loading. The pressure prevents the wearer's blood from being forced down to the lower areas of the body, ensuring the brain is not deprived of blood, since that deprivation is the cause of blackouts.
The first G-suit was developed by a team led by Wilbur R. Franks at the University of Toronto's Banting and Best Institute in 1941. The G-suits were made to be used by the Royal Air Force pilots during the war.
A new design of G-suit has been developed in Germany, called the Libelle G-suit. It is filled with liquid. As the pilot is subjected to G-forces, the liquid is pushed down to the pilot's leg by the same G-force. The result is a much faster response than the pneumatic version. Preliminary testing shows that pilot wearing the Libelle G-suit can withstand a force of 10G with ease while the same pilot can barely withstand 9G wearing a regular G-suit. 'Libelle' is the German word for dragonfly, the inspiration for the idea.
| The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia ( https://en.wikipedia.org/wiki/g-suit ). Apparel Industry definition modified by Apparel Search 8/2/06 |
Most clothing protects against the environment outside the body. The g-suit protects against a failure inside it: under acceleration, the cardiovascular system cannot keep blood at head height unaided. The suit is therefore a medical device worn as clothing, plumbed into the aircraft's air supply and controlled by a valve that reads the g load and inflates the bladders to match, harder as the turn tightens, releasing as the load comes off. Coverage varies by design, from trousers with bladders over the calves, thighs and abdomen to fuller suits, but the principle has not changed since 1941: external pressure substitutes for the blood pressure the heart cannot maintain.
The g-suit is rarely worn alone as a visible garment. It goes over or under parts of the flight suit system, integrated with the harness and the aircraft connection, and astronauts wear g protection for the acceleration of launch and re-entry on the same principle. Its development tracks aircraft performance: as jets pulled higher g for longer, suits had to respond faster and squeeze harder, which is exactly the problem the liquid Libelle design solves by letting the g-force itself drive the liquid. Among special suits, the g-suit is the one whose absence is measured in seconds: a few seconds of blackout in a manoeuvring fighter is the difference the suit exists to make.
Under high g, blood is forced toward the feet, and the brain, starved of blood, blacks out. The g-suit inflates air bladders over the legs and lower body in proportion to the g load, squeezing the lower body so blood stays up where it is needed. The pilot's own straining works with the suit, and together they raise the g a human can tolerate while staying conscious and in control.
The first g-suit was developed by a team led by Wilbur R. Franks at the University of Toronto's Banting and Best Institute in 1941. The suits were made for Royal Air Force pilots during the war, as fighter aircraft became fast and manoeuvrable enough to black out their own pilots in tight turns.
A newer design developed in Germany, filled with liquid instead of compressed air. As the pilot is subjected to g-forces, the liquid is pushed down toward the pilot's legs by the same g-force, squeezing automatically with no valves or air supply to respond first, so its response is much faster than the pneumatic version. In preliminary testing a pilot in the Libelle suit could withstand 10g with ease where the same pilot could barely withstand 9g in a regular g-suit. Libelle is the German word for dragonfly, the inspiration for the idea.