The AV-8B Harrier II is a fixed-wing vertical/short takeoff and landing (V/STOL) aircraft. Its ability to take off vertically makes it one of the most maneuverable combat aircraft in service, and it can zoom out of the range of enemy fire extremely quickly. The United States, Spain and Italy coordinated efforts to develop the AV-8B Harrier II Plus, which first flew Sept. 22, 1992. Prime contractors were McDonnell Douglas Aerospace and British Aerospace. The AV-8B Harrier II Plus, with a more powerful engine and advanced radar and avionics, can operate efficiently in darkness and in adverse weather conditions.