A flight suit is an article of clothing specially designed to withstand the rigors and demands of flight. These garments are used by military and civilian aviators as well as astronauts. While, historically, flight suits consisted of multiple pieces, modern designs are typically made as one-piece jumpsuits or coveralls.
Purpose-designed flight suits date back to World War I, as open cockpit flight demanded warm, padded apparel that could keep pilots comfortable in a wide range of conditions. The most common World War I-era flight suit was a two-piece leather design. By World War II, bomber and fighter planes could reach altitudes of more than 30,000 feet (9,144 m), but were not pressurized. Electrically-heated flight suits were introduced to keep bomber crews and pilots warm. Later, the development of pressurized cabins meant cabin crews no longer needed to be so protected from the elements, and the flight suit evolved to become less bulky and more form-fitting.
As jet engines were introduced onto civilian and military aircraft, the increased speeds and greater potential dangers associated with fires led to the development of fire-retardant flight suits. In addition, a special type of flight suit, known as the G-Suit, was introduced to help pilots maintain consciousness during extreme maneuvers. These worked by compressing the body and making it more difficult for fainting, or blackouts, to occur. The most complex flight suits are fully pressurized and are used by pilots who fly aircraft on the edge of space.
Astronauts, who are subjected to even greater extremes than other aviators, wear custom-fitted flight suits, known as launch-and-entry suits, during the initial launch into space. Each suit is supplied with a number of safety features, including a supplemental oxygen supply, emergency parachute, life raft, water supply, and homing beacon. During normal operation, once out in space, modern astronauts typically wear light cotton apparel rather than a flight suit.
The most common modern flight suits are made out of either a lightweight nylon-based material, known as NOMEX, that is highly durable and flexible; or a blended cotton and polyester material. Typically these garments feature a number of zippered closures to prevent stored articles from falling out in flight. While civilian and commercial airplane pilots do not commonly wear flight suits, they are fairly standard among helicopter pilots. In the United States, Army, Air Force, Navy, and Marine Corps pilots all wear the same model flight suit, designated as CWU-27/P by these military branches.