question: How do flight suits or g suits work and what do they do for military jet pilots?
comment: One of the effects of high Gs is that your blood pools in your legs - it's pushed to the outside of the curve along with the rest of your body. This causes blackouts as your brain is deprived of oxygen. G suits have inflatable sections in the thighs that squeeze the legs tight and prevent the blood from pooling there, keeping it in the upper body (ideally the brain).
passages: Section::::Design.
   This suit was worn by US pilots towards the end of the World War II.
   As early as 1917, there were documented cases of pilots' loss of consciousness due to g (G-LOC) that were referred to as "fainting in the air".
   Air-based g-suits were very common in NATO aircraft of all nations from the 1950s onwards and are still in common use today.
  
  Later jets such as the F-15 Eagle, F-16 Fighting Falcon, F/A-18 Super Hornet, Eurofighter Typhoon and the Dassault Rafale can sustain high g loads for longer periods, and are therefore more physically demanding. By using a modern g-suit in combination with anti-g strain techniques, a trained pilot is now expected to endure accelerations of up to nine g without blacking out.
   Also, with the coming of jet flight came the development of the G-suit, a special kind of flight suit (worn alone or in combination with a traditional flight suit) that protected the wearer from the physical stress of acceleration by compressing the body to keep blood from pooling in the legs. As the pilot executed high-G combat maneuvers, his blood would literally be pulled from his head and shift downwards into his lower body, starving the brain of oxygen and causing a blackout. The G-suit was designed to allow some retention of blood in the pilot's head, allowing him to execute high-G turns for sustained periods of time.
   Pilots in Red Bull Air Race World Championship have worn a g-suit called g-Race Suit since the 2009 season. The g-race suit is a liquid (water) filled, autonomous and aircraft independent working full-body g-protection system. It is tailor-made for each pilot and can be fine adjusted via lacings.
   G-suit
  
  A g-suit, or the more accurately named anti-g suit, is a flight suit worn by aviators and astronauts who are subject to high levels of acceleration force (g). It is designed to prevent a black-out and g-LOC (g-induced loss of consciousness) caused by the blood pooling in the lower part of the body when under acceleration, thus depriving the brain of blood. Black-out and g-LOC have caused a number of fatal aircraft accidents.
  
  Section::::Operation.
   Section::::Examples.
  
  BULLET::::- The U.S. Army's Demilitarization Protective Ensemble
  
  BULLET::::- The ILC Dover Chemturion "Blue Suit"
  
  BULLET::::- The Delta Protection "Orange Suit"
  
  BULLET::::- The Sperian Protection "White Suit"
  
  Section::::In fiction and film.
   The first g-suits were developed by a team led by Wilbur R. Franks at the University of Toronto's Banting and Best Medical Institute in 1941. The suits were manufactured by the Dunlop company and first used operationally in 1942 by the Fleet Air Arm (FAA) during Operation Torch. These devices used water filled bladders around the legs and two" 'Mk.' "versions (or Marks) were developed:
  
  BULLET::::- Franks Mark I suits were used by RAF Hurricane and Spitfire pilots;
  
  BULLET::::- Franks Mark II suits were used by the United States Army Air Forces and Royal Canadian Air Force pilots.
   The G-1 remains a current uniform-issue item in naval aviation for officer and enlisted aviation personnel on flying status in the U.S. Navy, U.S. Marine Corps and U.S. Coast Guard ("i.e.," Naval Aviator, Naval Flight Officer, Naval Flight Surgeon, Naval Aircrewman, etc.) and is arguably best known as the leather flight jacket worn by Tom Cruise in the film "Top Gun".
  
  Section::::Development.
   Section::::History.:'Berger' Gradient Pressure Suit.
   A G-suit is worn by aviators and astronauts who are subject to high levels of acceleration ('G'). It is designed to prevent a black-out and g-LOC (gravity-induced Loss Of Consciousness), due to the blood pooling in the lower part of the body when under G, thus depriving the brain of blood.
  
  Section::::Human centrifuge training.
  
  Human centrifuges are exceptionally large centrifuges that test the reactions and tolerance of pilots and astronauts to acceleration above those experienced in the Earth's gravity.
   Their efforts finally culminated with the release of the first US military design in late 1943: the GPS (Gradient Pressure Suit) type fighter pilot's G-1 anti-g-suit. The team subsequently worked on developing further, more advanced models in 1944 and beyond.
  
  Although uncomfortable and distracting to use, later research showed that military fighter pilots who wore g-suits survived and defeated their opponents in greater numbers than those who didn't.
  
  Modern g-Suits meet the United States Air Force Standard CSU-13B/P and United States Navy Standard CSU 15 A/P.
  
  Section::::Uses.
  
  Section::::Uses.:Prone pilot position aircraft.
   Section::::History.:Cotton Aerodynamic Anti-G Flying Suit.
   The "g" thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the "G"-straining manoeuvre can black out between 4 and 6 "g", particularly if this is pulled suddenly. A trained, fit individual wearing a "g" suit and practicing the straining manoeuvre can, with some difficulty, sustain up to 12-14"g" without loss of consciousness. The “Blue Angels” have to perform their maneuvers without the aid of flight-suits, and regularly sustain 3-5 second bursts of 10 ‘g’ thresholds. 
  
  Section::::See also.
  
  BULLET::::- G-suit
  
  BULLET::::- Redout
  
  BULLET::::- g-forces
   Members of the United States Marine Corps wore flight suits during most vehicle patrols and ground combat operations in Iraq and Afghanistan, because their standard camouflage utilities were not flame-resistant. Flight suits have now been phased out among ground personnel with the introduction of the Flame Resistant Organizational Gear, or "FROG" suit, which resembles the standard camouflage utilities.
  
  Section::::Space flight.
   In 1931 a professor of physiology, Frank Cotton, from the University of Sydney described a new way of determining the center of gravity of the human body. This made it possible to describe the displacement of mass within the body under acceleration.. Cotton had recognised the need for an anti-gravity suit during the 1940 Battle of Britain. It was estimated that 30% of pilot deaths were due to accidents, including black-out. Spitfires, in particular, were capable of rapid turns that generated high g-forces, causing black-out when diving to avoid or deliver enemy fire.
   Modifications to USN, USMC, and USCG uniform regulations in the 1990s reduced the type and number of permissible insignia on the G-1, but concurrently permitted wear of the G-1 jacket off base with service uniforms.
  
  Section::::Commercial exploitation.
   BULLET::::- Avalanche: Sgt. Ian M. Costello is the G.I. Joe team's cold weather specialist who drives the "Dominator" vehicle. It's said that he was a poacher when young. He is KIA in "G.I. Joe: A Real American Hero" #113 while maneuvering through an oil field, when it is bombed by Cobra Commander.
   To protect the pilot during operation of the Sonic Diver, a nanoskin gel is applied over the entire skin. This is made up of nanomachines. This coating lasts only for exactly 21 minutes and 32 seconds, but during that time the body is protected from the rigors of both flight and combat. Piloting it in the absence of a nanoskin gel is referred to as extremely dangerous and probably fatal.
  
  BULLET::::- Delta Lock and Quadra Formation
   Various designs of g-suit have been developed. They first used water-filled bladders around the lower body and legs. Later designs used air under pressure to inflate the bladders. These g-suits were lighter than the liquid-filled versions and are still in extensive use. However, the Swiss company Life Support Systems AG and the German collaborated to design the new Libelle suit for use with the Eurofighter Typhoon aircraft, which reverts to liquid as the medium and improves on performance. The Libelle suit is under consideration for adoption by the United States Air Force.
  
  Section::::History.
   Section::::History.
   Astronauts wear g-suits similar to aviators but face different challenges due to the effects of microgravity. Aviator g-suits apply uniform pressure to the lower legs to minimize the effects of high acceleration but research from the Canadian Space Agency implies there might be a benefit in having a suit for astronauts that uses a "milking action" to increase blood flow to the upper body.
  
  Section::::Uses.:Red Bull Air Race.
   High-G training
  
  High-G training is done by aviators and astronauts who are subject to high levels of acceleration ('G'). It is designed to prevent a g-induced loss of consciousness (G-LOC), a situation when the action of "g"-forces move the blood away from the brain to the extent that consciousness is lost.
  
  Incidents of acceleration-induced loss of consciousness have caused fatal accidents in aircraft capable of sustaining high-"g" for considerable periods.
   Section::::G5C suits.
  
  For the 14-day Gemini 7 mission, both Frank Borman and Jim Lovell wore modified G3C suits, but incorporating several changes:
  
  BULLET::::- Replacement of the pressure helmet and neck ring with a zippered hood incorporating a clear, fixed polycarbonate visor, with the astronauts wearing modified Navy-style aviator crash helmets that incorporated the communication equipment (microphones and earphones).
  
  BULLET::::- Additional zippers for in-flight adjustment, along with provisions for complete removal of the suit.
  