Westland Wallace

Infobox Aircraft
name=Westland Wallace


caption=
type=Two-seat general-purpose biplane
manufacturer=Westland
designer=
first flight=31 October 1931
introduced=1933
retired=1943
status=out of service
primary user=Royal Air Force
more users=
produced=1933-1936
number built=104 + 68 conversions from Wapitis
unit cost=
variants with their own articles=The Westland Wallace was a British two-seat, general-purpose biplane of the Royal Air Force, developed by Westland as a follow-on to their successful Wapiti. As the last of the inter-war general purpose biplanes, it was used by a number of frontline and Auxiliary Air Force Squadrons. Although the pace of aeronautical development caused its rapid replacement in front line service, its useful life was extended into the Second World War with many being converted into target tugs and wireless trainers. In 1933 a Westland Wallace became the first aircraft to fly over Mount Everest, as part of the Houston Mount Everest Expedition. [The Times, 15 February 1933.]

Design and development

In 1931, Westland produced the PV-6, a private-venture development of its successful Wapiti. This updated aircraft embodied a number of improvements including a lengthened fuselage, brakes and wheel spats on the undercarriage and a new engine. By this time both the appearance and performance differed considerably from the standard Wapiti, so the company designated it the "PV6 Wallace." Compared with the earlier Wapiti, the Wallace was 20 inches (0.5 m) longer, incorporated an improved undercarriage and was powered by a 655-hp (488-kW) Bristol Pegasus IV engine. The first batches of MK I Wallaces were conversions of Wapitis, a total of 68 powered by 570-bhp (425-kW) Pegasus IIM3 engines.

Westland designed an improved version, the Mk II which fitted with a more powerful engine and the then-novel idea of an enclosed canopy over both crew positions. This offered greater comfort for the crew and improved the rear gunner's aim by protecting him from the slipstream. Three Wallace Is ("K4346"-"K4348") were later converted to Mk II standards, including fitting the closed canopy.

Operational history

The original PV-6 prototype, registered "G-ACBR" (and also known as the Houston-Wallace) along with Westland PV-3 "G-ACAZ", was part of the Houston Everest Expedition, an attempt to fly over Mount Everest. Both aircraft received modifications that included fitting heating and oxygen equipment, fully enclosing the rear cockpits and using highly supercharged Bristol Pegasus IS 3 engines. James 2008, p.22-23.] Flown by Flight Lieutenant D.F. McIntyre, the two aircraft became the first to fly over Mount Everest on 3 April 1933. James 2008, p. 24.]

Most of the Wallaces served with the Auxiliary Air Force: 501, 502, 504, 608 and 610 squadrons. Others operated with the Anti-Aircraft Co-operation Flight at Biggin Hill

When withdrawn from the general purpose role, many Wallaces were converted into target tugs. A total of 83 Wallaces remained in service at the beginning of the Second World War. The last were withdrawn in 1943.

Variants

* Westland PV-6 - Prototype, later converted to military configuration as a Wallace I.
* Wallace Mk I - Conversion from Wapiti powered by a 570-hp (425-kW) Bristol Pegasus IIM3 engine, 68 converted.
* Wallace Mk II - New aircraft with glazed cockpit and powered by a 680-hp (506-kW) Bristol Pegasus IV engine, 104 built.

Operators

; UK
* Royal Air Force
** No. 501 Squadron RAF
** No. 502 Squadron RAF
** No. 503 Squadron RAF
** No. 504 Squadron RAF

pecifications (Westland Wallace II)

aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref=The Hamlyn Concise Guide to British Aircraft of World War II [ Mondey 1994, p.226 .]

crew=2
capacity=
length main= 34 ft 2 in
length alt= 10.41 m
span main= 46 ft 5 in
span alt= 14.15 m
height main= 11 ft 6 in
height alt= 3.51 m
area main= 488 ft²
area alt= 45.34 m²
airfoil=
empty weight main= 3,840 lb
empty weight alt= 1,742 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 5,750 lb
max takeoff weight alt= 2,608 kg
more general=
engine (prop)=Bristol Pegasus IV
type of prop=radial piston
number of props=1
power main= 680 hp
power alt= 507 kW
power original=
max speed main= 158 mph
max speed alt= 137 knots, 254 km/h
max speed more= at 15,000 ft (4,570 m)
cruise speed main= 135 mph
cruise speed alt=117 knots, 217 km/h
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 470 miles
range alt=409 nm, 756 km
ceiling main= 24,100 ft
ceiling alt= 7,435 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
guns=2 x 0.303 inch (7.7 mm) machineguns
bombs=total of 580 lb (263 kg) of bombs
avionics=

ee also

aircontent
related=
similar aircraft=
* Hawker Hardy
* Vickers Vincent
* Westland Wapiti
lists=* list of aircraft of the Royal Air Force
see also=

References

Notes

Bibliography

* James, Derek. "To The Top of the World". "Aeroplane". Vol 36 No. 4, Issue No 420, April 2008, pp. 20-25.
* Mondey, David. "The Hamlyn Concise Guide to British Aircraft of World War II". London: Aerospace Publishing, 1994. ISBN 1-85152-668-4.

External links

* [http://www.1000aircraftphotos.com/Contributions/Braas/4081.htm Westland Wallace Mk II]