The United States Naval Air Corps was a term denoting the portion of the United States Navy made up of United States Naval Aviators. The term was especially in use before and during World War II. Unlike the United States Army Air Corps (later United States Army Air Forces), the Naval Air Corps had no organizational structure. Administratively, naval aviation was the responsibility of the Bureau of Aeronautics, formed in 1921. From 1943 on, there was also a Deputy Chief of Naval Operations for aviation.