Westland Whirlwind (helicopter)

Westland Whirlwind (helicopter). The Westland Whirlwind was a British-built utility helicopter developed and produced by Westland Aircraft under license from the American Sikorsky Aircraft company. An anglicized version of the Sikorsky H-19 Chickasaw, it served extensively with the Royal Air Force, the Royal Navy, and other military and civilian operators worldwide from the mid-1950s. Renowned for its reliability, the Whirlwind performed in diverse roles including search and rescue, troop transport, and anti-submarine warfare, forming a cornerstone of British rotary-wing aviation for decades.

Development and design

The Whirlwind's origins lie in a 1951 license agreement between Westland Aircraft and Sikorsky Aircraft to manufacture the American Sikorsky S-55, designated as the Sikorsky H-19 Chickasaw by the United States Air Force. Westland adapted the design for British production, initially fitting it with the Alvis Leonides radial piston engine. This powerplant, built by Alvis Limited, necessitated a distinctive redesigned forward fuselage with a downward slope to accommodate the engine, differing from the Sikorsky S-55's original configuration. Subsequent development, particularly for the Royal Navy, saw the introduction of turbine-powered variants using the de Havilland Gnome turboshaft, a license-built version of the General Electric T58, which significantly improved performance and reliability. This turbine transition was a critical step in the helicopter's evolution, directly influencing the design of its more powerful successor, the Westland Wessex.

Operational history

Entering service with the Royal Air Force in 1954, the Whirlwind quickly proved its worth. The RAF Search and Rescue Force became a primary operator, with Whirlwinds performing countless lifesaving missions around the coasts of the United Kingdom and in other theaters like Cyprus and Hong Kong. The Royal Navy employed both piston and turbine variants from vessels such as aircraft carriers and cruisers, using them for plane guard duties, troop transport, and later, equipped with dunking sonar, for anti-submarine warfare. The helicopter saw active military service in numerous conflicts, including the Malayan Emergency, the Korean War, the Suez Crisis, and the Indonesia–Malaysia confrontation. Beyond the British armed forces, it was widely exported, serving with the Royal Australian Navy, the Indian Navy, and the Bundeswehr, among others.

Variants

The Whirlwind was produced in numerous series, primarily distinguished by their powerplants. Early Series 1 and 2 aircraft were powered by the Alvis Leonides piston engine. The major turbine-powered versions began with the Series 3, fitted with a single de Havilland Gnome. Key military designations included the HAR.1 for the Royal Air Force and the HAS.7 for the Royal Navy; the latter was a dedicated anti-submarine warfare model featuring dunking sonar and the ability to carry torpedoes or depth charges. The civil market was served by variants like the Series 3, used by operators such as Bristow Helicopters for offshore oil support. The final production model was the HAR.10, an improved search and rescue variant for the RAF.

Operators

The primary military operator was the United Kingdom, through the Royal Air Force, Royal Navy, and British Army. Significant export customers included the Royal Australian Navy, which operated them from the aircraft carrier HMAS Melbourne, and the Indian Navy. In Europe, the Bundeswehr of West Germany and the Royal Norwegian Air Force were notable operators. Other global operators included the Ghana Air Force, the Royal Saudi Air Force, and the Iraqi Air Force. Civilian and commercial operators were widespread, with Bristow Helicopters and the United Kingdom's Royal National Lifeboat Institution using them extensively.

Specifications (Westland Whirlwind HAS.7)

* **Crew:** 2 * **Capacity:** 10 passengers or 8 troops * **Length:** 42 ft 2 in (12.85 m) * **Rotor diameter:** 53 ft 0 in (16.15 m) * **Height:** 13 ft 4 in (4.06 m) * **Empty weight:** 5,075 lb (2,302 kg) * **Max takeoff weight:** 8,000 lb (3,629 kg) * **Powerplant:** 1 × de Havilland Gnome H.1000 turboshaft engine * **Maximum speed:** 109 mph (175 km/h, 95 kn) * **Range:** 320 mi (510 km, 280 nmi) * **Armament:** Could carry two torpedoes or depth charges for anti-submarine warfare.

Survivors

Several Whirlwinds are preserved in museums globally. In the United Kingdom, examples are held by the Fleet Air Arm Museum at RNAS Yeovilton and the Royal Air Force Museum Cosford. A HAR.10 is displayed at the Norfolk and Suffolk Aviation Museum. Internationally, a former Royal Australian Navy Whirlwind is part of the collection at the Fleet Air Arm Museum (Australia) at HMAS Albatross. Other preserved airframes can be found at the South African Air Force Museum in Pretoria and the Musée de l'Air et de l'Espace near Paris.