Westland WS-51 Dragonfly

The Westland WS-51 Dragonfly helicopter was built by Westland Aircraft and was a license-built version of the American Sikorsky S-51. Apart from military use, it was sold into civilian use.

Design and development
In December 1946 an agreement was signed between Westland Aircraft and Sikorsky to allow a British version of the S-51 to be manufactured under license in the United Kingdom. These would be powered by the 500 hp Alvis Leonides radial engine. A modified version was also developed by Westland as the Westland Widgeon, but it was commercially unsuccessful.

Operational history
The Dragonfly entered service with the Royal Navy in 1950 in the air-sea rescue role. A number were also used by the Royal Air Force for casualty evacuation. It was replaced in British service by the Westland Whirlwind, another derivative of a Sikorsky design, in the late 1950s.

Fifty-one civilian WS-51s were produced. Examples were used by Pest Control Ltd for crop spraying and others were flown as executive transports by Silver City Airways, Evening Standard Newspapers and Fairey Aviation. Exported aircraft operated in Japan, Belgian Congo, Mexico and Norway.

Variants

 * Westland/Sikorsky WS-51
 * Prototype.


 * Dragonfly HR.1
 * Air-sea search and rescue helicopter for the Royal Navy powered by a 540 hp Alvis 50 radial piston engine. 13 built, some modified later as HR.5s.


 * Dragonfly HC.2
 * Casualty evacuation helicopter for the Royal Air Force similar to the commercial Mark 1A, 2 built.


 * Dragonfly HR.3
 * Air-sea search and rescue helicopter for the Royal Navy. Similar to the Dragonfly HR.1, but fitted with all-metal rotor blades, 71 built some later modified as HR.5s.


 * Dragonfly HC.4
 * Casualty evacuation helicopter for the RAF similar to the Dragonfly HR.3 with all-metal rotor blades, 12 built.


 * Dragonfly HR.5
 * Air-sea search and rescue helicopter for the Royal Navy similar to the Dragonfly HR.3. Modified from HR.1 and HR.3.


 * Westland-Sikorsky WS-51 Mk.1A
 * Civil transport helicopter powered by a 520 hp (388 kW) Alvis Leonides 521/1 radial piston engine. Built by Westland in the United Kingdom, 36 built.


 * Westland-Sikorsky WS-51 Mk.1B
 * Civil transport helicopter powered by a 450 hp (336 kW) Pratt & Whitney R-985 Wasp Junior B4 radial piston engine, 15 built.

Military and Government Operators

 * 🇪🇬 Egypt
 * Egyptian Air Force
 * 🇭🇰 Hong Kong
 * Hong Kong Police Force
 * 🇮🇹 Italy
 * Italian Air Force
 * 🇹🇭 Thailand
 * Royal Thai Air Force
 * Empire Test Pilots' School
 * Royal Air Force
 * Far East Casualty Evacuation Flight RAF
 * No. 194 Squadron RAF
 * Royal Navy
 * Britannia Royal Naval College/Britannia Helicopter Flight
 * 700 Naval Air Squadron
 * 701 Naval Air Squadron
 * 705 Naval Air Squadron
 * 727 Naval Air Squadron
 * 728 Naval Air Squadron
 * 744 Naval Air Squadron
 * 771 Naval Air Squadron
 * SFR Yugoslav Air Force
 * SFR Yugoslav Air Force
 * SFR Yugoslav Air Force

Civil Operators

 * Sabena
 * British European Airways
 * Silver City Airways
 * British European Airways
 * Silver City Airways

Survivors
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 * Dragonfly HR.1 VZ962 on display at the Ta'Qali Museum, Malta.
 * Dragonfly HR.3 WG725 in Nowra, New South Wales, Australia
 * Dragonfly HR.5 VX595 on display at the Fleet Air Arm Museum, Somerset, United Kingdom
 * Dragonfly HR.5 WG719 on display at The Helicopter Museum, Somerset, United Kingdom.
 * Dragonfly HR.5 WG724 on display at the North East Aircraft Museum, Tyne and Wear, United Kingdom.
 * Dragonfly HR.5 WG751 on display at the Chatham Historic Dockyard, Kent, United Kingdom.
 * Dragonfly HR.5 8-1 on display at the Aviodrome, Lelystad, Netherlands.
 * Dragonfly HR.5 WH991 on display at the Yorkshire Air Museum, North Yorkshire, United Kingdom.
 * Dragonfly HR.5 WN493 on display at the Fleet Air Arm Museum, Somerset, United Kingdom.
 * Dragonfly HR.5 WN499 on display at AeroVenture, South Yorkshire, United Kingdom.
 * Dragonfly HR.5 WP495 on display at RAF Museum Cosford, Shropshire, United Kingdom. Marked are G-AJOV.
 * Dragonfly HR.5 on display at the Sri Lanka Air Force Museum, SLAF Ratmalana, Sri Lanka.
 * Westland/Sikorsky S-51 Dragonfly on display at the Museu Eduardo André Matarazzo, Bebedouro, SP, Brazil.
 * Westland-Sikorsky WS-51 Mk.1A H1-4/96 (cn WA/H/120) at Royal Thai Air Force Museum, Don Muang AFB, Thailand
 * Westland-Sikorsky WS-51 Mk.1B 11503 on display at the Yugoslav Aeronautical Museum, Belgrade, Serbia.