An unmanned aerial vehicle (UAV)

A RQ-2 Pioneer, a reconnaissance UAV of theRomanian Air Force during the Gulfand Iraq Wars.

Although most UAVs are fixed-wing aircraft, rotorcraft designs such as this MQ-8B Fire Scout also exist.

A MQ-9 Reaper, a hunter-killersurveillance UAV used by the United States Armed Forces andBritish Armed Forces, especially inIraq and Afghanistan.

An unmanned aerial vehicle (UAV), commonly referred to as a drone^[1] is a remotely piloted aircraft. UAVs come in two varieties: some are controlled from a remote location, and others fly autonomously based on pre-programmed flight plans using more complex dynamic automation systems. Currently, UAVs perform reconnaissance as well as attack missions. Drone attacks often kill civilians.^[1][2]

UAVs are also used in a small but growing number of civil applications, such as firefighting. UAVs are often preferred for missions that are too "dull, dirty, or dangerous" for manned aircraft.

There is a wide variety of UAV shapes, sizes, configurations, and characteristics. For the purposes of this article and to distinguish UAVs from missiles, a UAV is defined as capable of controlled, sustained, level flight and powered by a jet orreciprocating engine. Cruise missiles are not classed as UAVs, because, like many other guided missiles, the vehicle itself is a weapon that is not reused, even though it is also unmanned and in some cases remotely guided.

The abbreviation UAV has been expanded in some cases to UAVS (unmanned-aircraft vehicle system). The Federal Aviation Administration has adopted the generic class unmanned aircraft system (UAS) originally introduced by the U.S. Navy to reflect the fact that these are not just aircraft, but systems, including ground stations and other elements.

Main article: History of unmanned aerial vehicles

The earliest UAV was A. M. Low's "Aerial Target" of 1916.^[3] A number of remote-controlled airplane advances followed, including the Hewitt-Sperry Automatic Airplane, during and after World War I, including the first scale RPV (Remote Piloted Vehicle), developed by the film star and model airplane enthusiast Reginald Denny in 1935.^[3] More were made in the technology rush during the Second World War; these were used both to train antiaircraft gunners and to fly attack missions. Jet engines were applied after WW2, in such types as the Teledyne Ryan Firebee I of 1951, while companies like Beechcraft also got in the game with their Model 1001 for the United States Navy in 1955.^[3] Nevertheless, they were little more than remote-controlled airplanes until the Vietnam Era.

Front view of a MQ-1 Predator(Reno Air Show)

With the maturing and miniaturization of applicable technologies as seen in the 1980s and 1990s, interest in UAVs grew within the higher echelons of the US military. UAVs were seen to offer the possibility of cheaper, more capable fighting machines that can be used without risk to aircrews. Initial generations were primarily surveillance aircraft, but some were fitted with weaponry (such as the MQ-1 Predator, which utilized AGM-114 Hellfire air-to-ground missiles). An armed UAV is known as an unmanned combat air vehicle (UCAV).

The near future will likely see unmanned aircraft employed, offensively, for bombing and ground attack. As a tool for search and rescue, UAVs can help find humans lost in the wilderness, trapped in collapsed buildings, or adrift at sea. While air-to-air combat will likely remain the last domain of the human pilot, when unmanned fighter jets do come about, they will enjoy the advantage of almost unlimited immunity to G-force effects.

In the future, UAVs will be able to take full advantage of scramjet technology. Today's scramjets, while unmanned, see use only for testing purposes (e.g., NASA X-43A, NASA's Hyper-X scramjet program), but have the potential when developed for combat to out-maneuver even the most experienced pilots.