USS Langley (CV-1/AV-3) was the United States Navy's first aircraft carrier, converted in 1920 from the collier USS Jupiter , and also the US Navy's first turbo-electric-powered ship. Conversion of another collier was planned but canceled when the Washington Naval Treaty required the cancellation of the partially built Lexington-class battlecruisers Lexington and Saratoga, freeing up their hulls for conversion to the aircraft carriers Lexington and Saratoga. Langley was named after Samuel Langley, an American aviation pioneer. Following another conversion to a seaplane tender, Langley fought in World War II. On 27 February 1942, while ferrying a cargo of USAAF P-40s to Java, she was attacked by nine twin-engine Japanese bombers of the Japanese 21st and 23rd naval air flotillas and so badly damaged that she had to be scuttled by her escorts. She was also the only carrier of her class.

An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Carriers have evolved since their inception in the early twentieth century from wooden vessels used to deploy balloons to nuclear-powered warships that carry numerous fighters, strike aircraft, helicopters, and other types of aircraft. While heavier aircraft such as fixed-wing gunships and bombers have been launched from aircraft carriers, these aircraft have not landed on a carrier. By its diplomatic and tactical power, its mobility, its autonomy and the variety of its means, the aircraft carrier is often the centerpiece of modern combat fleets. Tactically or even strategically, it replaced the battleship in the role of flagship of a fleet. One of its great advantages is that, by sailing in international waters, it does not interfere with any territorial sovereignty and thus obviates the need for overflight authorizations from third-party countries, reduces the times and transit distances of aircraft and therefore significantly increases the time of availability on the combat zone.