The Westland Whirlwind (AKA: "Westland's" or "Westlands") was a British licence-built version of the U.S. Sikorsky S-55/H-19 Chickasaw. It was used in the UK by Royal Navy's Fleet Air Arm in anti-submarine and search and rescue roles, RAF search and rescuers, Bristow Helicopters and British European Airways. It was sold to several overseas military.
Westland Aircraft was building the American Sikorsky S-51 under license as the Westland Dragonfly by 1950 and purchased both the rights to manufacture and sell Sikorsky's larger Sikorsky S-55 helicopter under a diferent name after converting the design to meet British standards, including the provision of a revised main-rotor gearbox.
The first prototype British aircraft was registered under the I.D. number "G-AMJT". It was powered by the 600 hp Pratt & Whitney R-1340-40 Wasp engine did not fly until August 1953. This was followed by ten Whirlwind HAR.1s and had a larger 700 hp Wright R-1300-3 Cyclone 7 engine.
Westland Helicopters was economically dieing in the 1980s and was the victim of the 1985–86 Westland affair. Italy's Agusta Helicopters finally bought Westland Helicopters and was it's self later bought out by Italy's Leonardo-Finmeccanica.
Aircraft ownership in the breakup of Yugoslavia:[]
Some stored out of use in Bosnia (factional control unknown).