An X-47B Unmanned Combat Air System (UCAS) demonstrator aircraft is transported on an aircraft elevator aboard the aircraft carrier Harry S. Truman (CVN 75).

The term drone has been used from the early days of aviation to name remotely-flown target aircraft used for practice firing a battleship's guns, such as the 1920s Fairey Queen and 1930s de Havilland Queen Bee. An unmanned aerial vehicle (UAV) is defined as a "powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely. UAV is a term that is commonly applied to military use cases. Missiles with warheads are not considered UAVs because the vehicle itself is a munition. The term unmanned aircraft system (UAS) was adopted by the United States Department of Defense (DoD) and the United States Federal Aviation Administration (FAA) An unmanned combat aerial vehicle (UCAV), also known as a combat drone is used for intelligence, surveillance, target acquisition, and reconnaissance and carries aircraft ordnance such as missiles, machine guns, and bombs.