As aircraft became faster and more sophisticated, the equipment that their pilots wore had to adapt as well. It became clear that the human body was not naturally able to cope with the stresses that flying in these modern aircraft put on it.  One of the main issues was G-force, which in simple terms is the increase in gravity due to acceleration.   For example, if you are on a roller coaster that is said to have a force of 3G, would feel 3 times as heavy as normal gravity.  In these new, modern aircraft G-force can be very great and high G force makes blood gather in the lower extremities of the body, which can deprive the brain of oxygen.  As such, pilots can pass out when exposed to 4-6 Gs.  To combat this, along with breathing techniques, pilots utilize G-Suits to keep the blood from collecting in the legs.

This film takes a hilarious look at testing ejection seats.  One major hurdle in the development of these escape mechanisms is that they produce a very large G Force, and often the pilot would black out, making it hard to survive the ejection.

In the San Diego Air & Space Museum's curatorial collection, we have a unique example of a G-Suit, one that belonged to one of the original Mercury 7 astronauts, Wally Schirra.  Prior to going into space in the Mercury, Gemini and Apollo programs, Wally Schirra was a pilot in the United States Navy, serving in Korea, where he flew 90 combat missions and downed 2 enemy Migs.  After the war, he served as a test pilot.  Schirra flew many types of aircraft, including the F-84 Thunderjet, the F4D Skyray, the F11F Tiger, and the F8U Crusader.  After his illustrious carreer, he retired in San Diego, and became a good feind of the our Museum.  He and his family donated much of his collection, which included this G-Suit. How the suit works is very simple, air in pumped into it via a hose, and the air pressure constricts the legs, forcing blood to remain in the upper parts of the body 

Schirra's "Anti-G" coveralls were made by Rubber Fabricators, inc and are type Z3.

Although we do not know exactly when Schirra used our G-suit, it is quite possible he is wearing it in this photo of the Mercury 7 astronauts in front of a Convair F-106. 

In this image from an Italian magazine, astronauts Grissom and Schirra train to combat "G-the terrible stresses of launching and landing."

Feel free to enjoy viewing more Curatorial items here and more images from the Schirra collection here.