|The last surviving Airspeed Envoy, operated by Private Charter Ltd at Manchester (Ringway)Airport in 1948|
|National origin||United Kingdom|
|Designer||A. H. Tiltman|
|First flight||26 June 1934|
Development and design
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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.
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aircraft was due to fly in the MacRobertson Air Race from England to Australia in 1934 but the aircraft was damaged and withdrawn from the race.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 King's Flight took delivery of an Envoy III as a replacement for a de Havilland Dragon Rapide. The aircraft received the registration G-AEXX and was painted in distinctive red and blue colours.
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. Three months later they ordered four more Envoys.
With the acquisition of a licence, production started at the Nagoya Mitsubishi factory of the Mitsubishi Hinazuru-type Passenger Transport, initially powered by Gasuden Jimpu engines, but later using licence 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 licence-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 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. One of the Nationalist Envoys flew into a mountain in June 1937, killing General Emilio Mola; this Envoy had been their demonstrator and was sold for £6000 cash (six £1000 Bank of England notes).
One of the RAF Envoy IIIs survived the war and was operated by Private Charter Ltd as G-AHAC for civil passenger charter flights until it was scrapped at Tollerton airport, Nottingham during 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
- 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 345-hp (257-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
- AS.8 Viceroy
- A special, one-off racing aircraft was developed from the Envoy: the Airspeed AS.8 Viceroy.
- Airspeed LXM
- One imported Airspeed Envoy evaluated by the Imperial Japanese Navy Air Service
- Mitsubishi Hinazuru-type Passenger Transport
- (Hinazuru - en Young Crane)Licence production by Mitsubishi, fitted with flaps and powered by Gasuden Jimpu, or licence-built Armstrong Siddeley Lynx or Wolseley Aries Mk.III engines. Eleven built from 1936 to 1938
Accidents and incidents
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 a large long-range fuel tank filling the middle of the cabin.
Maxwell Findlay fatally crashed another Envoy, modified with long-range fuel tanks, in northern Rhodesia during the October 1936 Portsmouth to Johannesburg Schlesinger African Air Race. They were to use a Viceroy purchased for £5500; but when offered £9500 (the cost of the plane plus the first prize of £4000) by a Spanish (war) buyer they cashed the cheque and ordered a Cheetah-engine Envoy with long range tanks which had similar performance to the Viceroy. But at Abercorn in Africa they could not wait for the wind to drop so they could take off downhill. They took off with maximum load uphill against the wind but failed to clear trees beyond the strip and crashed.
The Envoy prototype (demonstrator) was sold to the Spanish Nationalists for £6000 cash (six £1000 Bank of England notes) in September 1936 and used as a VIP transport. On 3 June 1937 it flew into a mountain killing all on board including General Mola.
Specifications (AS.6J Series III )
Data from Airspeed Aircraft since 1931
- Crew: 1 pilot
- Capacity: 6 passengers
- Length: 34 ft 6 in (10.52 m)
- Wingspan: 52 ft 4 in (15.95 m)
- Height: 9 ft 6 in (2.90 m)
- Wing area: 339 sq ft (31.5 m2)
- Empty weight: 4,057 lb (1,840 kg)
- Gross weight: 6,300 lb (2,858 kg)
- Powerplant: 2 × Armstrong Siddeley Cheetah IX 7-cylinder radial engine, 345 hp (257 kW) each
- Maximum speed: 210 mph (338 km/h; 182 kn) at 7,300 ft (2,230 m)
- Cruise speed: 192 mph (309 km/h; 167 kn) at 75% power and 7,300 ft (2,230 m)
- Range: 650 mi (565 nmi; 1,046 km) at 62.5% power and 10,000 ft (3,050 m)
- Service ceiling: 22,500 ft (6,900 m) service
- Time to altitude: to 10,000 ft (3,050 m), 8 min
- Wing loading: 18.6 lb/sq ft (91 kg/m2)
- Power/mass: 0.11 hp/lb (0.18 kW/kg)
- Jackson 1973, p. 20.
- Taylor 1970, pp. 54–70.
- "One out of nine." Flight, 8 October 1936, pp. 352–354.
- Jackson 1973, p. 23.
- Jackson 1973, p. 21.
- Shute, Slide Rule 1954, p. 226.
- Jackson 1973, p.392—393.
- Howson 1979, pp.68—78.
- Slide Rule 1954, p. 233.
- Ketley and Rolfe 1996, p. 11.
- Slide Rule 1954, pp. 221-224.
- Shores et al. 1990, p. 155.
- Hamlin 2001, p. 11
- Taylor 1970, pp. 69–70.
- Norway, Neville Shute (1954). Slide Rule. London: William Heinemann.
- Hamlin, John. The Oxford, Consul & Envoy File. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 2001, ISBN 0 85130 2890
- Howson, Gerald. "Contraband Wings of the Spanish Civil War...Britain's Clandestine Contribution". Air Enthusiast 10, July–September 1979, pp. 68–78.
- Jackson, A. J. British Civil Aircraft since 1919: Volume 1 (2nd ed.). London: Putnam, 1973. ISBN 0-370-10006-9.
- Ketley, Barry and Mark Rolfe. Luftwaffe Fledglings 1935-1945: Luftwaffe Training Units and their Aircraft. Aldershot, UK: Hikoki Publications, 1996. ISBN 978-0-9519899-2-0.
- Shores, Christopher F. et al. Above the Trenches: A Complete Record of the Fighter Aces and Units of the British Empire Air Forces 1915-1920. London: Grub Street, 1990. ISBN 978-0-948817-19-9.
- Taylor, H. A. Airspeed Aircraft since 1931. London: Putnam Publishing, 1970, pp. 69–70. ISBN 0-370-00110-9.
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