Airspeed AS.6 “Envoy”
British twin-engine low-wing monoplane light transport
Archive Photos ¹
Airspeed AS.6 “Envoy” Commercial Monoplane (G-ADCA) (Historic photo via Jane's 1936) 4
Airspeed AS.6 “Envoy” (Collector card images from the Skytamer Archive ¹)
- Airspeed AS.6 Envoy
- Role: Transport
- Manufacturer: Airspeed Ltd.
- Designer: A. H. Tiltman
- First flight: 26 June 1934
- Retired: 1950
- Produced: 1937-1938
- Number built: 60
- Variants: Airspeed Viceroy, Airspeed Oxford
The Airspeed AS.6 Envoy was a British light, twin-engined transport aircraft designed and built by Airspeed Ltd. in the 1930s at Portsmouth Aerodrome, Hampshire.
Development and Design ²
The Envoy was designed by A. H. (Hessell) Tiltman as a twin-engined development of his earlier Courier. It used the same wooden construction, outer wing panels and innovative retracting main undercarriage.
The Envoy was a twin-engined low-wing cabin monoplane of all-wood construction apart from fabric covered control surfaces. It had a rearward retracting main undercarriage with a fixed tailwheel. The aircraft was built in three series, the Series I was the initial production variant which did not have trailing-edge flaps, seventeen built. Thirteen Series II variants were built with split flaps and the Series III (19-built) was similar but had detailed improvements. Each series of the Envoy was sold with a choice of engines including the Wolseley Aries, Armstrong Siddeley Cheetah V or Armstrong Siddeley Lynx IVC radial engines. These different engines were housed under a variety of cowlings, mostly short chord Townend rings but also wider chord cowlings with and without blisters for cylinder heads.
The prototype (G-ACMT), first flew on 26 June 1934 and in July 1934 appeared in public for the first time at an exhibition by the Society of British Aircraft Constructors (SBAC) at Hendon. Small-scale production then began at the Portsmouth factory.
Operational History ²
The first production Envoy I (G-ACVH), flew in October 1934 and was used as a company demonstrator. The second, also a Series I but fitted with Wolseley Aries III radial engines, was delivered to Lord Nuffield. This aircraft was due to fly in the MacRobertson Air Race from England to Australia in 1934 but the aircraft was damaged and withdrawn from the race. Another aircraft, a specially modified version with long-range tanks (the AS 8 Viceroy) got as far as Athens before leaving the race due to damage. One Envoy took part in the Schlesinger Race to Johannesburg, but crashed, killing two of a crew.
Orders soon came from the whole Commonwealth. Two aircraft went to the Ansett Airlines in Australia. North Eastern Airways and Olley Air Service in the UK also used the AS.6. In Czechoslovakia, the CSA ordered four AS.6 Envoy JC in 1937.
In May 1937, the British King George VI traded the de Havilland Dragon Rapide of the King's Flight for an Airspeed AS.6J Envoy III. The AS.6's good stability and flaps, as well as its low landing speed (less than 100 km/h) was decisive. The aircraft received the registration G-AEXX and was painted in distinctive red and blue colors.
The Airspeed AS.6 Envoy also entered the Air Forces of different countries. The British Royal Air Force used a few AS.6 in a military configuration. The aircraft was used in the Air Forces of Spain, Japan, South Africa, Finland and China and some others. Seven machines were ordered for joint use by the South African Air Force and South African Airways, with three being delivered in military form and four delivered to South African Airways, where they were used on the air route between Johannesburg - Bloemfontein - Port Elizabeth on 12 October 1936. Each of these seven aircraft could be transformed by a work crew of four within four hours from the transport version into a light bomber or reconnaissance aircraft. In this configuration the crew consisted of four; pilot, navigator, radio operator and gunner.
In October 1936, the British Air Ministry ordered 136 Envoys for crew training. These further developed aircraft were given a new company designation as the AS.10 and entered RAF service as the Airspeed Oxford.
Two Envoy-Is were delivered to Japan in 1935, one for evaluation by the Japan Air Transport Co. (NKYKK - Nihon Koku Yuso KK) and one for the Imperial Japanese Navy Air Service as the Airspeed LXM. With the acquisition of a license, production started at the Nagoya Mitsubishi factory of the Mitsubishi Hinazuru-type Passenger Transport, initially powered by Gasuden Jimpu engines, but later using license built Armstrong Siddeley Lynx or Wolseley Aries Mk.III engines. Mitsubishi built aircraft also had landing flaps which were not fitted to Airspeed built Envoys. Flight testing of the Jimpu powered aircraft resulted in a crash, killing the flight test observer, (the first fatality during flight testing of Mitsubishi aircraft), blamed on the engines producing excessive drag, resulting in the switch to license built British engines. Eleven aircraft were built at Nagoya before production ceased, all of which flew domestic services for NKYKK (later to become Greater Japan Airways).
During the Spanish Civil War, ten Airspeed AS.6 Envoys were obtained by the Spanish Republicans, with the Nationalist side using two, including one that defected from the Republicans, as transport, reconnaissance aircraft or light bombers.
During the Second World War, the German Luftwaffe captured some machines and used them as trainer aircraft. The Luftwaffe gave one aircraft to Finland on 22 January 1942, as reparation for the accidental shooting down of a Finnish de Havilland Dragon Rapide. This aircraft was used between 1942 and 1943. Likewise, one aircraft was used between 1941 to 1943 by the Slovaks.
One of the RAF Envoy IIIs survived the war and operated as G-AHAC for civil charter operators until it was scrapped at Tollerton airport, Nottingham in 1950.
Airspeed Ltd, Portsmouth
- AS.6 Envoy I: Powered by two 200-hp (149-kW) A.R.9 piston engines. 5 built.
- AS.6A Envoy I: Powered by two 240-hp (179-kW) Armstrong Siddeley Lynx IVC radial piston engines. 5 built
- AS.6D Envoy II: Powered by two 350-hp (261-kW) Wright R-760-E2 Whirlwind 7 radial piston engines, eight built.
- AS.6E Envoy III: Powered by two 340-hp (254-kW) Walter Castor engines. 5 built
- AS.6G: Powered by two 250-hp (186-kW) Wolseley Scorpio I engines.
- AS.6H Envoy: Powered by two 225-hp (168-kW) Wolseley Aries III engines. 1 built
- AS.6J Envoy III: Seven-seat light transport aircraft. Powered by two 350-hp (261-kW) Armstrong Siddeley Cheetah IX radial piston engines. 27 built
- AS.6JC Envoy: Powered by two 350-hp (261-kW) Armstrong Siddeley Cheetah IX radial piston engines. 4 built
- AS.6JM Envoy: Powered by two 350-hp (261-kW) Armstrong Siddeley Cheetah IX radial piston engines. 3 built
- AS.6K Envoy III: Three-built.
- AS.8 Viceroy: A special, one-off racing aircraft was developed from the Envoy.
- Airspeed LXM: One imported Airspeed Envoy evaluated by the Imperial Japanese Navy Air Service
- Mitsubishi Hinazuru-type Passenger Transport: (Hinazuru - en Young Crane) License production by Mitsubishi, fitted with flaps and powered by Gasuden Jimpu, or license-built Armstrong Siddeley Lynx or Wolseley Aries Mk.III engines. Eleven built from 1936 to 1938
- Australia: Ansett Airlines
- Croatia: Air Force of the Independent State of Croatia
- Czechoslovakia: CSA
- Finland: Finnish Air Force
- Germany: Luftwaffe (small numbers)
- Japan: Japan Air Transport; Imperial Japan Airways
- Manchukuo: Manchukuo National Airways
- South Africa: South African Airways operated four aircraft; South African Air Force
- Spain: Spanish Republican Air Force from LAPE
- Spain: Spanish Air Force
- United Kingdom: North Eastern Airways; Olley Air Service; Private Charter Ltd; Royal Air Force No. 24 Squadron RAF
Accidents and Incidents ²
- December 1934:
Cheetah-powered Envoy (VH-UXY), piloted by Charles Ulm, disappeared in December 1934 during an attempt to fly the Pacific route between Oakland and Honolulu. It had been specially built with long-range fuel tanks in the cabin.
- October 1936:
Maxwell Findlay fatally crashed another Envoy, modified with long-range fuel tanks, in northern Rhodesia during the October 1936 Johannesburg Air Race.
Specifications (AS.6, Woseley AR.9) ³
- Twin-engine, low-wing, transport
- Crew: 1 pilot
- Capacity: 6 passengers
Weights and Loadings
- Span: 52 ft 4 in (15.94 m)
- Length: 34 ft 6 in (10.53 m)
- Height 9 ft 6 in (2.9 m)
- Wing area: 339 ft² (31.5 m²)
- Empty weight, inclusive of all equipment: 3,077 lbs (1,395 kg)
- Pilot: 170 lbs (77 kg)
- Fuel (78 gal, 355 L): 600 lbs (273 kg)
- Oil (8 gal, 36.4 L): 76 lbs (34.5 kg)
- Disposable load: 2,223 lbs (1,010 kg)
- Balance available for payload, etc: 1,377 lbs (625 kg)
- Loaded weight: 5,300 lbs (2,405 kg)
- Wing loading: 15.6 lb/ft² (76.2 kg/m²)
- Power loading: 13.5 lb/hp (6.13 kg/hp)
- 2 × Woseley Aries, 225-hp, 9-cylinder, single row, radial engine
- Maximum speed at sea level: 170 mph (273 km/h)
- Cruising speed at 1,000 ft (305 m): 150 mph (241 km/h)
- Best climbing speed: 97 mph (156 km/h)
- Stalling speed with full load: 63 mph (101 km/h)
- Landing speed: 55 mph (88.5 km/h)
- Take-off run (no wind): 265 yd (242 m)
- Initial rate of climb: 914 ft/min (4.65 m/sec)
- Service ceiling: 17,000 ft (5,180 m)
- Range at cruising speed: 403 miles (650 km)
- 3-view drawing & Collector Card Images: The Skytamer Archive, copyright © 2013 Skytamer Images. All Rights Reserved
- History: Wikipedia, Airspeed Envoy
- Specification and performance data: Taylor, H. A., Airspeed Aircraft since 1931. London: Putnam Publishing, 1970, pp. 69–70. ISBN 0-370-00110-9.
- Photo: Grey, C.G. and Leonard Bridgeman. Jane's All The World's Aircraft. London: Sampson Low, Marston & Company, Ltd., 1936. pp. 16c-18c.
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