Hawker Siddeley Harrier and better equipped for air defence, to replace their AV-8S Harriers; this investigation did not progress to a purchase. The last first-generation Harriers were retired by Thailand in 2006. Hawker Siddeley Harrier The Hawker Siddeley Harrier, developed in the 1960s, is the first of the Harrier Jump Jet series of aircraft. It was the first operational close-support and reconnaissance fighter aircraft with vertical/short takeoff and landing (V/STOL) capabilities and the only truly successful V/STOL design of the many that arose in that era. The Harrier was developed directly from the Hawker Siddeley Kestrel prototype aircraft, following the cancellation of a
British Aerospace Harrier II programme. In July 2008, Qinetiq was awarded a contract to perform upgrades and maintain the Harrier II fleet until 2018, which was the predicted out of service date for the type. The first squadrons to receive the Harrier II were based in Royal Air Force Germany, a standing force maintained to deter Soviet aggression against the West and, in the event of war, to carry out ground attacks. As the Harrier II had significantly greater range and survivability than its predecessor the Hawker Siddeley Harrier, a new emphasis was placed on interdiction operations. By the end of 1990, the Harrier