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
Hawker Siddeley Harrier for more sudden braking and higher turn rates. Braking could cause a chasing aircraft to overshoot and present itself as a target for the Harrier it was chasing, a combat technique formally developed by the USMC for the Harrier in the early 1970s. The two largest users of the Harrier were the Royal Air Force and the United States Marine Corps (USMC). The exported model of the aircraft operated by the USMC was designated the AV-8A Harrier, which was broadly similar to the RAF's Harrier GR.1. Changes included the removal of all magnesium components, which corroded quickly at sea, and