Man flying 3DR RTF X8 drone near River Mersey, Merseyside, England

An unmanned aerial vehicle (UAV), commonly known as a drone, as an unmanned aircraft system (UAS), or by several other names, is an aircraft without a human pilot aboard. The flight of UAVs may operate with various degrees of autonomy: either under remote control by a human operator, or fully or intermittently autonomously, by onboard computers. Here, an owner flies a medium sized drone over the river Mersey, close to Runcorn, Widnes, Fiddlers Ferry and the new toll crossing, which is under construction. Civilian drones now vastly outnumber military drones, with estimates of over a million sold by 2015.