Westland Wapiti

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Wapiti
Wapiti of 55 Squadron RAF
Role General purpose
National origin United Kingdom
Manufacturer Westland Aircraft
Designer Arthur Davenport
First flight 7 March 1927[1]
Introduction June 1928
Primary users Royal Air Force
Royal Indian Air Force
Royal Canadian Air Force
Royal Australian Air Force
Number built 558 + 27 licence built in South Africa[1]
Variants Westland Wallace
Westland PV-3

The Westland Wapiti was a British two-seat general-purpose military single-engined biplane of the 1920s. It was designed and built by Westland Aircraft Works to replace the Airco DH.9A in Royal Air Force service.

First flying in 1927, the Wapiti entered service with the RAF in 1928, and remained in production until 1932, a total of 565 being built. It equipped twenty squadrons of the RAF, both overseas (particularly in India and Iraq) and at home, remaining in RAF service until 1940, also being used by the Air Forces of Australia, Canada, South Africa and India. It also formed the basis for the Westland Wallace which partly replaced the Wapiti in RAF use.

The Wapiti is named for the

wapiti, also known as elk, one of the largest species of the deer
family and one of the largest land mammals in North America and eastern Asia.

Design and development

In 1927, the British Air Ministry issued Specification 26/27 for a replacement of the elderly Airco DH.9A, designed during the First World War which still equipped the Royal Air Force's General Purpose squadrons. To save time and money, the specification called for the use of a high proportion of DH.9A components, (as the RAF still held large stores of DH.9A spares), while it encouraged the use of an all-metal structure.[2] A large number of types were tendered to meet this requirement from most of the major British aircraft manufacturers, including Westland, who submitted the design that later became known as the Wapiti. Westland had an advantage in that it had carried out the detailed design work for the DH.9A, and was already a major contractor for the DH.9A.[3]

The Wapiti was a conventional single-engined equal-span two-bay biplane with a slight wing stagger. It had tandem open cockpits and a fixed main undercarriage plus a tailskid. The forward fuselage was of metal tube structure with aluminium-and-fabric covering, while the rear fuselage was of fabric-covered wooden construction. The wings and tail were standard wooden DH.9A components,[4] although later models replaced the wooden parts with an all-metal structure. The Wapiti was powered by a single Bristol Jupiter radial engine, and its crew of two were armed with a forward-firing Vickers machine gun and a Lewis gun for the observer, while it could carry up to 580 lb (264 kg) of bombs under the wings and fuselage. It was also fitted with radio and photographic cameras, and like the DH.9A before it, could carry a spare wheel for operations in adverse terrain.[5]

The prototype first flew on 7 March 1927.[6] Initial tests showed poor control, and the prototype was modified with a much larger tail and horn-balanced ailerons, solving these problems. (It was later discovered that a 2-foot (0.61 m) fuselage section had been omitted from the prototype – as handling was now acceptable, it was not reinstated.)[7] The Wapiti performed well during RAF trials, while using significant amounts of DH.9A components, and was declared the winner of the competition, an initial contract for 25 aircraft being placed in October 1927.[8]

After initial production, the wooden fuselage, tail and wings were replaced by metal structures in the Wapiti II and IIA, and the original long fuselage was eventually reinstated in the Wapiti V and later versions. In 1930, Westland produced an updated version of the Wapiti, the Wapiti VII, which differed so much that it was renamed the Westland Wallace.

Operational history

RAF Wapitis in Gilgit, Kashmir around 1930

The type entered service with

Second World War
.

The prototype Wapiti V, registered G-AAWA, was used for demonstration flights in Argentina and Uruguay on floats, powered by a 550 hp Armstrong Siddeley Panther IIA engine.[10] It was later modified as the Bristol Pegasus-powered Westland PV-6 or Wapiti VII, re-registered G-ACBR (also known as the Houston-Wallace after the patron Lucy, Lady Houston), for an attempt to fly over Mount Everest. Flown by Flt Lt David F. McIntyre and accompanied by a Westland PV-3 the two aircraft became the first to fly over Mount Everest on 3 April 1933. The PV-6 was later designated the Wallace Mk I, bearing serial K3488 which introduced a number of improvements. A total of 68 Wapitis were converted to Wallace Mk I standard.

The Wapiti was used by the Indian Air Force into the early days of the Second World War. For example, during the Imperial Japanese Navy attack on Ceylon (now Sri Lanka), the Indian Air Force sent 2 Wapitis to patrol off the east coast of India, looking for the Japanese fleet. The southern patrolling Wapiti found nothing. But the northern patrolling Wapiti actually found a Japanese task force including the aircraft carrier Ryujo, and then amazingly survived to land undamaged.[11]

Military operators

 Australia
 Canada
 China
  • Chinese Nationalist Air Force
 Kingdom of Hejaz
IndiaIndia
 South Africa
 United Kingdom

(in India)

(in Iraq)

(in the United Kingdom)

Variants

All built by Westland at Yeovil

Surviving aircraft

Westland Wapiti K-813 at the Indian Air Force Museum , New Delhi.

A Westland Wapiti (Serial Number K-813) survives at the Indian Air Force Museum, Palam, Delhi. It is the last surviving aircraft of the type. The fuselage and lower wing of one other (Serial Number K-811) were reported as surviving at the museum's storage facility, but in June 2012 it was determined that only K-811's lower wing survives, albeit in a ruinous condition.[citation needed]

Specifications (Wapiti IIA)

Data from The British Bomber since 1914[24]

General characteristics

  • Crew: 2
  • Length: 31 ft 8 in (9.65 m)
  • Wingspan: 46 ft 5 in (14.15 m)
  • Height: 13 ft (4.0 m)
  • Wing area: 488 sq ft (45.3 m2)
  • Empty weight: 3,810 lb (1,728 kg)
  • Gross weight: 5,410 lb (2,454 kg)
  • Powerplant: 1 ×
    Bristol Jupiter VI
    9-cylinder air-cooled radial piston engine, 420 hp (310 kW)
  • Propellers: 2-bladed fixed-pitch propeller

Performance

  • Maximum speed: 129 mph (208 km/h, 112 kn)
  • Cruise speed: 110 mph (180 km/h, 96 kn) [25]
  • Range: 360 mi (580 km, 310 nmi)
  • Service ceiling: 18,800 ft (5,700 m)
  • Rate of climb: 1,140 ft/min (5.8 m/s) [26]
  • Time to altitude: 15 minutes to 10,000 ft (3,000 m)
  • Wing loading: 11.1 lb/sq ft (54 kg/m2)
  • Power/mass: 0.0776 hp/lb (0.1276 kW/kg)

Armament

See also

Related development

Aircraft of comparable role, configuration, and era

References

Notes

  1. ^ a b "Aircraft Data Sheet: Wapiti (1927) Wapiti". Westland Helicopters. Retrieved 9 February 2008.
  2. ^ James 1991, p.139.
  3. ^ Jarrett Aeroplane July 1994, p.59.
  4. ^ Jarrett Aeroplane July 1994, p.59–60.
  5. ^ James 1991, pp.141–142.
  6. ^ James 1991, p.142.
  7. ^ Janes 1991, pp.142–143.
  8. ^ Mason 1994, pp.188–189.
  9. Aeroplane Monthly
    September 1994, p.17.
  10. ^ Jackson p.509
  11. ^ Shores, Christoper, Cull, Brian, and Izawa, Yasuho; Bloody Shambles, volume two, Grub Street publishers, London, 1993, Pages 408, 410.
  12. ^ The Westland Wapiti II in Indian Air Force Service Archived 2013-07-28 at the Wayback Machine
  13. ^ No. 104 (GR) Squadron, Indian Air Force Archived 2008-01-16 at the Wayback Machine
  14. ^ James 1991, p.144.
  15. ^ James 1991, p.146.
  16. ^ a b James 1991, p.148.
  17. ^ Jarrett Aeroplane Monthly July 1994, pp.61–62.
  18. ^ James 1991, pp. 148–149.
  19. ^ a b James 1991, p.153.
  20. ^ Mason 1994, p.190.
  21. ^ Jarrett Aeroplane Monthly July 1994, p.62.
  22. ^ a b James 1991, p.156.
  23. ^ James 1991, p.157.
  24. ^ Mason 1994, p.189.
  25. ^ James 1991, p.158.
  26. ^ Thetford 1957, p.455.

Bibliography

External links

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