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 vessel. Since then the Sea Control Ship concept has been subject to periodic re-examinations and studies, often in the light of budget cuts and questions over the use of supercarriers. Other exercises were performed to demonstrate the AV-8A's suitability for operating from various amphibious assault ships and aircraft carriers, including a deployment of 14 Harriers aboard for six months in 1976. The tests showed, amongst other things, that the Harrier was capable of performing in weather where conventional carrier aircraft could not. In support of naval operations, the USMC devised and studied several methods to further integrate the Harrier. One