The Air Force views UAVs as an essentially remote-controlled aircraft, but it does not mean that there the aircraft has completely unmanned control. In fact, there is an operator involved in the flight of these systems, but such operator does not need to be inside the aircraft. The operator may remotely control the air vehicle with a stick and rudder control, or program the vehicle and it autonomously decides how to change and adjust its flight.
The use of UAVs was predetermined by the necessity of intelligence surveillance and reconnaissance operations in different parts of the world. UAVs are relatively small aircraft but many defense analysts consider such vehicles to be crucial for military affairs. For example, "UAV can find, identify, and even direct a precision munition to a target, and then assess the damage done to that target after the munition has hit, without risking the lives of an aircrew. UAVs are also appealing to the military because different UAV systems can collect different types of information, such as tactical (or battlefield) intelligence and strategic (or longer-range) intelligence. In addition, UAVs may be able to perform such roles as relaying messages during a battle, locating or jamming enemy radar, or monitoring areas during peacekeeping missions" (CBO, http://www.fas.org/man/congress/1998/cbo-uav3.htm). Such impressive results reaffirm the idea of effective use of such vehicles in mission areas for air power needs and warfare.
The use of UAVs started from destination of aerial targets, and then the Air Force started to use them for intelligence, surveillance and reconnaissance needs. UAVs were first used extensively to conduct reconnaissance missions during the Vietnam War. During this war, UAV was a leading edge intelligence gathering tool and the aircraft that saved human lives. The United States began serious development of such vehicles after their essential involvement in the variety of programs, which led to several reconnaissance drones, such as the Firefly and Lightning Bug (CBO, http://www.fas.org/man/congress/1998/cbo-uav3.htm). The first UAVs were difficult to operate and maintain, however, the Air Force used them for a variety of missions, including gathering signals intelligence and collecting high- and low-altitude imagery both during the day and at night. In Vietnam, UAVs were primarily used for intelligence, surveillance and reconnaissance. During the Vietnam War, the U.S. even found that UAVs could become attack aircraft. U.S. forces used remotely controlled UAVs with launching a guided Maverick ground attack missiles at different targets. After the war, UAVs provided surveillance over areas of China, North Vietnam and the Far East that were too dangerous for manned aircraft. During the missions, UAVs' tasks included the supply of tactical information to commanders that satellites could not.
After the Vietnam War, the U.S. Department of Defense began to develop a new UAV which would be free from many shortcomings exhibited by UAVs during the war. In 1979, a new UAV, the Aquila, was built. The Aquila included evasive maneuver, night-time target designation and anti-jam data