Wilbur Rounding Franks was born on March 4th, 1901, in Weston, Ontario (Leary, 2000). Franks attended the University of Toronto, graduated with a degree in medicine, and trained in cancer research. While Sir Frederick Banting was the first person to recognize the G-force complication, in 1941 Franks and his team designed, and tested the first ever G-suit (Leary 2000). They called it the Franks Flying Suit Mark II. The suit comprised two layers of rubber overalls laced together, with liquid between each layer. It was capable of protecting pilots from a maximum six G's, which none of the fighters at that time could exceed. Although Frank's suit was impractical, Franks later built a suit that functioned by air compression (pneumatic suit), instead of liquid compression. This suit was successful and went into production, and is still in use today (Leary 2000). During the Second World War, Franks also fabricated the first Canadian human centrifuge. He used the system to train pilots to operate their aircraft while encountering high G-forces (Phillipson, 2006). Wilbur Franks died on January 4th 1986 (Phillipson, 2006).
Aviation holds many problems for fighter pilots today, one of them being G-forces. A G-force is a gravitational acceleration (John, 2005). When accelerating quickly the body will experience positive G's, and depending on the intensity of the acceleration, the body's mass will increase. For example, at 2G acceleration a human body with a mass of 170 lbs will experience twice the normal gravitational force, and weigh 240 lbs (Leary, 2000). There are three types of acceleration; linear acceleration, radial, or centripetal acceleration, and angular acceleration. Linear acceleration is a change in speed, but without a change in direction, for example an aircraft taking off. Radial or centripetal acceleration are a change in direction, for example a tight turn. Angular acceleration is both a change in speed, and a change in direction, for example an aircraft going into a tight spin (Anonymous, 2006). The G-suit has also been incorporated into the space-suit to protect astronauts from G-forces in the same way it protects pilots, but the suits face other problems due to the effects of microgravity.
When encountering acceleration or positive G's, the force is pushing downward on your body, and your blood from your upper body is being forced to your lower body, and away from your brain. The human heart is not powerful enough to pump the blood back up, because of the high forces that are holding it down. Therefore not enough oxygen gets to your brain, and gravity induced loss of consciousness (G-LOC) can occur (Libelle G-Multiplus, 2004). The first symptoms of G-LOC start with a gray out (loss of color), soon followed with tunnel vision, and lastly a complete blackout. These blackouts can last up to 20 seconds, with another 30 seconds to fully regain orientation, and be able to fly the aircraft properly (John, 2005). Blackouts can be fatal when carrying out low altitude basic fighter maneuvers (BFM), or dogfights.
Pilots are also prone to Negative G-forces, or deceleration, which can occur when the pilot is being forced out of his or her seat rather then into it. Negative G-forces push blood towards the brain, the contrary effect of positive G-forces, and can result in a red out, blood being forced into the eyes. No protection product has been introduced to counteract the forces of negative G's, so most pilots try to avoid negative G-forces by rolling the aircraft 180 degrees, and performing the maneuver upside down.
Although the average body can only handle up to 5G, some aircraft have the potential to accelerate up to 20G in less then a second (John, 2005). This is where the G-suit comes into play. The G-suit is what gives today's pilots the ability to battle the forces of gravity. As noted the first G-suit invented by Wilbur Rounding Franks was liquid based (Leary, 2000). The suit functioned when the forces acted upon the liquid, increasing the mass of the liquid, and compressing the leg (Leary, 2000). This prevented excess blood from entering the leg and being pulled away from the heart. This suit was succeeded by the pneumatic anti-g trousers (Leary 2000).The advantage of the trousers was that they could protect pilots from higher G's because they were connected to an anti-g pressure hose, which is connected to the pressure system on the aircraft that inflates the suit with compressed air from the engine (John, 2005). This compresses the lower body to minimize blood being trapped there (John, 2005). The suit contains four connected air chambers located in the lower abdomen, thighs, and lower leg (John, 2005). The air can inflate the suit to a very high pressure, to insure the protection at high G-forces (John, 2005).
The pneumatic system still faced some problems. It is a complicated system with switches, valves, and pumps and the suit can only be fully effective after 2 seconds of inflation, and after 2 seconds at 10G's the pilot could already be unconscious (John, 2005). Since the pneumatic system's release, combat aircraft technology has made many large innovations, and is becoming extremely advanced. Today's 4th generation combat aircraft have demonstrated their ability to be quite maneuverable, and have shown their potential to cause black-outs. But America's new 5th generation fighter, Lockheed Martins F-22 Raptor will be going into service in 2006, and the F-22 is so maneuverable that it can cause a black-out instantaneously, before the pilot experiences any G-LOC symptoms. (John, 2005) The 5th generation of combat aircraft has presented the problem that pneumatic gravitational force protection can be helpless when a need demands to rapidly accelerate.
Fortunately a Swiss company called "Autoflug Libelle has developed a new type of g-suit that is more efficient than the pneumatic suit. Their new suit uses the same principals as the original suit built by Franks. The suit fits around the entire body, and functions when the liquid is be acted upon by the G-forces, and in theory would protect the pilots from negative G's as-well as positive G's, and be able to counteract the effect on the blood circulation, at extremely high gravitational forces (Libelle, 2004). During a human centrifuge test, pilots wearing Libelle suits were unscathed under an extraordinary 12G for multiple seconds (Libelle, 2004).
Under immense G-force, three alternatives have been developed to deal with G-forces. The first way to help counteract G-forces is to breathe rapidly, and hold your breath. While holding your breath, tighten legs, and abdominal muscles, to prevent blood from being pushed into your legs. This is called the anti-G straining maneuver (AGSM) (Leary, 2000). The second alternative is called positive pressure breathing, and a mask is worn to force pressurized air into the lungs. However this approach has led to lung damage due to over inflation of the lungs (Leary, 2000). The last routine developed by the U.S Air Force called "Combat Edge", uses positive pressure breathing while wearing a countermeasure vest to protect the chest (Leary, 2000).
Combat aircraft have brought us to a conflict: Man vs. Machine, and has shown us that our own creations have truly exceeded our physical limitations. But as humans we continue to create innovative technologies such as G-suits. The G-suit has enabled us to do things beyond human potential, and we have surpassed our natural capabilities with a little help from our best friend, and worst enemy technology.
