Westland WS-51 Dragonfly


The Westland WS-51 Dragonfly helicopter was built by Westland Aircraft and is an Anglicised licence-built version of the American Sikorsky S-51.

Design and development

On 19 January 1947 an agreement was signed between Westland Aircraft and Sikorsky to allow a British version of the S-51 to be manufactured under licence 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.
After delays caused by the need to modify and convert American-drawings to reflect British-sourced items and to replace the engine with a British-built Alvis Leonides 50, the prototype was first flown from Yeovil on 5 October 1948 piloted by Alan Bristow. Only 16 months had elapsed since work had begun on building the prototype registered G-AKTW.
After evaluation initial orders for the British military were placed, thirteen Dragonfly HR.1s for the Royal Navy and three Dragonfly HC.2s for the Royal Air Force.

Operational history

A total of seventy-two Dragonfly helicopters entered service with the Fleet Air Arm of the Royal Navy in the training, air-sea rescue and communications roles. The first unit to be equipped with them was 705 Naval Air Squadron, which is believed to be the first all-helicopter squadron to be formed outside of the United States. The Dragonfly was the first British-built helicopter to be used by the navy and the first to operate from a British ship in trials on in 1951. A Dragonfly led the helicopter section of the flypast at the Coronation Review of the Fleet in 1953.
A planned upgrade the navy's Dragonflies to the Widgeon standard with a larger cabin, to be known as the Dragonfly HR.7, was dropped in 1957 due to defence cuts. It was replaced in British service by the Westland Whirlwind, another derivative of a Sikorsky design, in the late 1950s. Dragonflies were used in relief operations in the North Sea flood of 1953 and a number were used by the Royal Air Force for casualty evacuation during the Malayan Emergency.
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
;Dragonfly HR.1
;Dragonfly HC.2
;Dragonfly HR.3
;Dragonfly HC.4
;Dragonfly HR.5
;Westland-Sikorsky WS-51 Mk.1A
;Westland-Sikorsky WS-51 Mk.1B
;H.1

Operators

Military and government operators

Civil operators

Surviving aircraft

Australia
Brazil
Japan
Malta
Netherlands
Serbia
Sri Lanka
Thailand
United Kingdom
Venezuela