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Westland WS-51 Dragonfly

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TheWestland WS-51 Dragonflyhelicopter was built byWestland Aircraftand was anAnglicisedlicence-builtversion of the AmericanSikorsky S-51.

WS-51 Dragonfly
Dragonfly HR.3 of 705 Naval Air Squadron Royal Navy in 1955
General information
TypeRescue or communicationshelicopter
National originUnited Kingdom
ManufacturerWestland Aircraft
StatusRetired
Primary usersRoyal Navy
Number built149
History
Manufactured1949–1954
Introduction date1950
First flight5 October 1948
Developed fromSikorsky H-5
VariantsWestland Widgeon

Design and development

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On 19 January 1947 an agreement was signed betweenWestland AircraftandSikorskyto allow a British version of the S-51 to be manufactured under licence in the United Kingdom. These would be powered by the 500 hpAlvis Leonidesradial engine. A modified version was also developed by Westland as theWestland 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

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A total of seventy-two Dragonfly helicopters entered service with theFleet Air Armof theRoyal Navyin the training,air-sea rescueand communications roles. The first unit to be equipped with them was705 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 onRFAFort Duquesnein 1951.[1]A Dragonfly led the helicopter section of the flypast at theCoronation Review of the Fleetin 1953.[2]

A planned upgrade the navy's Dragonflies to the Widgeon standard with a larger cabin, to be known as theDragonfly HR.7,was dropped in 1957 due to defence cuts.[2]It was replaced in British service by theWestland Whirlwind,another derivative of a Sikorsky design, in the late 1950s. Dragonflies were used in relief operations in theNorth Sea flood of 1953and a number were used by theRoyal Air Forceforcasualty evacuationduring theMalayan Emergency.[1]

Fifty-one civilian WS-51s were produced. Examples were used by Pest Control Ltd for crop spraying and others were flown as executive transports bySilver City Airways,Evening Standard Newspapers andFairey Aviation.Exported aircraft operated in Japan, Belgian Congo, Mexico and Norway.[3]

Variants

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Westland/Sikorsky WS-51
Prototype.
Dragonfly HR.1
Air-sea search and rescue helicopter for the Royal Navy powered by a 540 hp (400 kW) Alvis 50 radial piston engine. 13 built, some modified later as HR.5s.
Dragonfly HC.2
Casualty evacuation helicopter for theRoyal Air Forcesimilar to the commercial Mark 1A, 2 built and one-conversion from a civil Mark 1A.
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 with Alvis Leonides 23/1 engine and updated to instruments and avionics. 25 modified from HR.1 and HR.3.
Westland-Sikorsky WS-51 Mk.1A
Civil transport helicopter powered by a 520 hp (388 kW)Alvis Leonides521/1 radial piston engine, 36 built.
Westland-Sikorsky WS-51 Mk.1B
Civil transport helicopter powered by a 450 hp (336 kW)Pratt & Whitney R-985Wasp Junior B4 radial piston engine, 15 built.

Operators

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Military and government operators

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Ceylon
Egypt
Iraq
Italy
Japan
Japan Maritime Self Defence Force S-51
Thailand
United Kingdom
British European Airways Sikorsky S-51 in 1953
Yugoslavia

Civil operators

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Belgium

Brazil

Japan
United Kingdom

Surviving aircraft

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WS-51 Mk.1A in Royal Thai Air Force Museum in December 2014

Australia

Brazil

Japan

Malta

Netherlands

HR.5 on static display at the Aviodrome in Lelystad, Netherlands.

Serbia

Sri Lanka

Thailand

United Kingdom

HR.1 at the FAA Museum in Yeovilton, England.

Venezuela

Specifications (WS-51 Mk.1A)

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Westland Dragonfly HR3

Data fromJane's all the World's Aircraft 1955–56[36]

General characteristics

  • Crew:1
  • Capacity:3 passengers (useful load 530 lb (240 kg)
  • Length:57 ft 6.5 in (17.54 m) overall
  • Fuselage length:41 ft 1.75 in (12.54 m)
  • Height:12 ft 11.375 in (3.95 m)
  • Empty weight:4,366 lb (1,980 kg) HR Mk.1,[a]
  • Gross weight:5,700 lb (2,585 kg)[b]
  • Max takeoff weight:5,870 lb (2,663 kg)
  • Fuel capacity:83 imp gal (100 US gal; 380 L) in 2 fuselage tanks
  • Powerplant:1 ×Alvis Leonides 521/19-cylinder air-cooled radial piston engine (6lb boost), 520 hp (390 kW)
  • Main rotor diameter:49 ft (15 m)
  • Main rotor area:1,885 sq ft (175.1 m2)[c]

Performance

  • Maximum speed:103 mph (166 km/h, 90 kn) at sea level[d]
  • Cruise speed:85 mph (137 km/h, 74 kn)[e]
  • Range:300 mi (480 km, 260 nmi) in still air with 20 minutes fuel reserves
    [f]
  • Service ceiling:11,000 ft (3,400 m)[g]

See also

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Related development

Related lists

Notes

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  1. ^HC Mk.44,380 lb (1,990 kg),HC Mk.24,450 lb (2,020 kg) including stretcher panniers
  2. ^HC Mk.2, HC Mk.4 5,870 lb (2,660 kg)
  3. ^Mk. 1A, Mk.1B, HR Mk.3 and HC Mk.4. Rotor diameter (HR Mk.1 and HC Mk.2) 48 ft (15 m), Rotor area (HR Mk.1 and HC Mk.2) 1,809 sq ft (168.1 m2)
  4. ^HR Mk.1, HR Mk.3 95 mph (83 kn; 153 km/h), HC Mk.2, HR Mk.3 88 mph (76 kn; 142 km/h)
  5. ^HC Mk.2, HC Mk.4 78 mph (68 kn; 126 km/h)
  6. ^HC Mk.2, HC Mk.4 275 mi (239 nmi)
  7. ^HR Mk.1 12,400 ft (3,800 m), HR Mk.3 13,200 ft (4,000 m)
    • Hover ceiling OGE:6,000 ft (1,800 m)
    HC Mk.24,600 ft (1,400 m)
    • Hover ceiling IGE:8,000 ft (2,400 m)
    HR Mk.15,600 ft (1,700 m)
    HR Mk.37,000 ft (2,100 m)
    • Best rate of climb HR Mk.1:800 ft/min (4.1 m/s) at sea level
    • Best rate of climb HR Mk.3:1,000 ft/min (5.1 m/s) at sea level
    • Vertical rate of climb HR Mk.1:50 ft/min (0.25 m/s) at sea level
    • Vertical rate of climb HR Mk.3:200 ft/min (1.0 m/s) at sea level

References

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Citations

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  1. ^ab"Westland Dragonfly HR.5: WG724".nelsam.org.uk.North East Land Sea and Air Museums.Retrieved7 July2021.
  2. ^abBeaver, Paul (1987).Encyclopaedia of the Fleet Air Arm Since 1945.Yeovil, Somerset: Patrick Stephens Ltd. p. 176.ISBN978-0850597608.
  3. ^abcdJackson 1974,pp. 618–619.
  4. ^"Worlds Helicopter Market 1968 pg. 50".flightglobal.com.Retrieved16 June2018.
  5. ^Sipos, Milos; Cooper, Tom (2020).Wings of Iraq, Volume 1: The Iraqi Air Force, 1931-1970.Warwick, UK: Helion & Company Publishing. p. 39.ISBN978-1-913118-74-7.
  6. ^"シコルスキーS-51 (ウェストランド/シコルスキー WS-51ドラゴンフライMk.1A)".KWATのほおむぺえじ nhất hào nhất hình.Retrieved18 October2023.
  7. ^"THE WORLD'S AIR FORCES 1955 pg. 658".flightglobal.Retrieved18 October2014.
  8. ^"World Air Forces 1955 pg. 631".flightglobal.com.Retrieved2 February2015.
  9. ^James 1991,p. 308.
  10. ^Jefford 1988,p. 134.
  11. ^ab"Westland S-5I".Flightglobal Insight. 1953.Retrieved18 October2014.
  12. ^abcdefHoward, Burrow & Myall 2011,pp. 11–35
  13. ^ab"Westland Dragonfly HR5 (WN493)".Fleet Air Arm. Archived fromthe originalon 28 September 2022.Retrieved28 January2015.
  14. ^"THE WORLD'S AIR FORCES 1955 pg. 668".flightglobal.Retrieved18 October2014.
  15. ^"Helicopters in Civil Operation pg. 388".flightglobal. 21 March 1958.Retrieved18 October2014.
  16. ^ab"きたかみ hào".Misawa Aviation & Science Museum.Retrieved26 April2020.
  17. ^Ballance 2016,p. 411.
  18. ^Crick, Darren; Edwards, Martin; Cowan, Brendan (29 June 2015)."RAAF A80 Sikorsky S-51 Dragonfly [and] RAN Westland Dragonfly".ADF-Serials.Retrieved15 June2019.
  19. ^"Turismo em Bebedouro".turismo.bebedouro.sp.gov.br.Retrieved12 July2024.
  20. ^"Main Exhibition Hangar".Malta Aviation Museum.Retrieved15 June2019.
  21. ^"Westland Dragonfly".Demobbed.Retrieved15 June2019.
  22. ^"Airframe Dossier - Sikorsky-Westland Dragonfly HR.3, s/n WG752 RN, c/n WA/H/062".Aerial Visuals.Retrieved15 June2019.
  23. ^"Сикорски С-51Мк-IB".Aeronautical Museum Belgrade.Archived fromthe originalon 3 April 2016.Retrieved15 June2019.
  24. ^"Airframe Dossier - Sikorsky-Westland Dragonfly 1A, s/n CH501 SLAF, c/n WA/H/137".Aerial Visuals.
  25. ^"Building 5".Royal Thai Air Force Museum.Archived fromthe originalon 26 October 2013.Retrieved15 June2019.
  26. ^Darke, Steve (26 December 2016)."ROYAL THAI AIR FORCE MUSEUM, DON MUEANG"(PDF).The Thai Aviation Website.Retrieved15 June2019.
  27. ^"Airframe Dossier - Sikorsky-Westland Dragonfly HR.5, s/n VX595".Aerial Visuals.Retrieved15 June2019.
  28. ^"[Untitled]".The Helicopter Museum.Archived fromthe originalon 30 October 2018.Retrieved15 June2019.
  29. ^"Exhibits".North East Land, Sea and Air Museums.Retrieved15 June2019.
  30. ^"c/n wa/h/061".Helis.com.Retrieved15 June2019.
  31. ^"Westland – Sikorsky Dragonfly HR.5".Yorkshire Air Museum.Retrieved15 June2019.
  32. ^"Westland Dragonfly HR5 (WN493)".Fleet Air Arm Museum.Archived fromthe originalon 28 September 2022.Retrieved15 June2019.
  33. ^"Aircraft List".South Yorkshire Aircraft Museum.Archived fromthe originalon 30 March 2018.Retrieved15 June2019.
  34. ^"OUR EXHIBITS".Morayvia.Retrieved15 June2019.
  35. ^"Airframe Dossier - Sikorsky-Westland Dragonfly HR.3".Aerial Visuals.Retrieved15 June2019.
  36. ^Bridgman, Leonard, ed. (1955).Jane's all the World's Aircraft 1955–56.London: Sampson Low, Marston & Company, Ltd. pp. 105–106.

Bibliography

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  • The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985).Orbis Publishing.
  • Howard, Lee; Burrow, Mick; Myall, Eric (2011).Fleet Air Arm Helicopters since 1943.Air-BritainHistorians Limited.ISBN978-0-85130-304-8.
  • Ballance, Theo (2016).The Squadrons and Units of the Fleet Air Arm.Air-Britain.ISBN978-0-85130-489-2.
  • Jackson, A.J. (1974).British Civil Aircraft Since 1919 – Volume Three.Putnam & Company Limited.ISBN0-370-10014-X.
  • James, D (1991).Westland Aircraft since 1915.London:Putnam Aeronautical Books.ISBN9780851778471.
  • Jefford, C G (1988).RAF Squadrons. A comprehensive record of the movement and equipment of all RAF squadrons and their antecedents since 1912.Shrewsbury:Airlife.ISBN1-85310-053-6.
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