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 Harrier it was underpowered, and it had an inferior bombload to the Hawker Horsley, the aircraft it was meant to replace. It was therefore modified to carry a torpedo. On testing the modified aircraft, however, it was found to still be underpowered, being incapable of taking off with a torpedo, gunner and full fuel load. It was therefore not considered further, the competition ultimately being won by the Vickers Vildebeest. The prototype was used by Bristol as an engine testbed, flying with the 870 hp (649 kW) Bristol Hydra and the Bristol Orion engines. Hawker Harrier The Hawker Harrier was an