Did you know a human being can normally withstand only up to 5G without passing out? During a flight, blood is pushed down to the legs which can cause a lack of blood in the head. In the worst case, it may lead to unconsciousness.
But with some muscle and breathing training, and a G-suit, a fighter pilot is able to withstand up to 9G. Breathing exercises like an anti-G straining maneuver involves rapid breathing followed by holding a breath for several seconds and tightening leg and stomach muscles at the same time.ut it is the G-suit that plays the main role in pushing the blood back up to the heart and brain. When the G forces increase, the G-suit inflates and adds 1 counter G. The inflation also adds pressure to the pilot’s body which acts as a reminder for the pilot to strain the muscles in the legs, abdomen, and chest area. The G-suit also inflates an air-pocket that adds pressure to the chest to ease breathing.
All this is to ensure that the pilot is able to maneuver the plane without losing sight or consciousness.
Recently, a series of tests were conducted to verify if Gripen E's anti-g systems worked fine. The focus was to verify that the system gave the correct pressure to the oxygen mask and G-suit depending on the actual altitude.