The de Havilland DH.34 was a single engined British

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

airliner built by the

de Havilland Aircraft Company The de Havilland Aircraft Company Limited () was a British aviation manufacturer established in late 1920 by Geoffrey de Havilland at Stag Lane Aerodrome Edgware on the outskirts of north London. Operations were later moved to Hatfield in H ...

in the 1920s. 12 were built, with the DH.34 serving with

Imperial Airways Imperial Airways was the early British commercial long-range airline, operating from 1924 to 1939 and principally serving the British Empire routes to South Africa, India, Australia and the Far East, including Malaya and Hong Kong. Passengers ...

and its predecessors for several years.

Design and development

By 1921, enough experience had been gained with operation of the de Havilland DH.18 to realise that aircraft needed to be more efficient to improve the economics of air travel. de Havilland therefore built the ten-passenger DH.29

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

, while starting work on the design of the DH.32, a

of similar size and capacity to the eight-passenger DH.18, but with a less powerful but more economical

Rolls-Royce Eagle The Rolls-Royce Eagle was the first aircraft engine to be developed by Rolls-Royce Limited. Introduced in 1915 to meet British military requirements during World War I, it was used to power the Handley Page Type O bombers and a number of oth ...

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

. Owing to the urgent need for more capacity, however, work on the DH.29 and DH.32 was stopped and the DH.34 biplane was designed, with a similar

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

to the DH.29, accommodating ten passengers. The DH.34 had a wooden,

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

-clad fuselage, with the

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls that e ...

(for two pilots) being positioned ahead of the wings and the passenger cabin. It had two-bay wooden wings and was powered by a

Napier Lion The Napier Lion is a 12-cylinder, petrol-fueled 'broad arrow' W12 configuration aircraft engine built by D. Napier & Son from 1917 until the 1930s. A number of advanced features made it the most powerful engine of its day and kept it in produ ...

engine, which was fitted for inertia starting, avoiding the necessity for hand swinging of the propeller to start the engine.Jackson, 1973, Unusually, the design of the aircraft allowed an entire spare engine to be carried on board across the rear of the passenger cabin. The cabin door's unusual shape was to allow the engine to be loaded and unloaded, and a specially-fitted 'porthole' on the other side of the cabin would be removed to allow the propeller boss to protrude out the side of the aircraft. Spare engines were not carried routinely (the DH.34's payload was too low to carry both passengers and a spare engine) but this facility was used by operators to quickly fly spare engines out to aircraft that had suffered breakdown. Two DH.34s were ordered by the

Daimler Airway Daimler Airway was an airline subsidiary of the Birmingham Small Arms Company (BSA)'s Daimler Company. It was created to use some of the assets of the failed ventures Airco and its subsidiary, Aircraft Transport and Travel, which was acquired ...

, as part of an initial batch of nine aircraft, with the first prototype (registered ''G-EBBQ'') flying on 26 March 1922. The stalling speed of was too high and was blamed for a fatal crash in 1923, so extensions were fitted to the upper wings, increasing the wingspan from .

Operational history

The DH.34 entered service with Daimler on 2 April 1922 on the

Croydon Croydon is a large town in south London, England, south of Charing Cross. Part of the London Borough of Croydon, a local government district of Greater London. It is one of the largest commercial districts in Greater London, with an exten ...

-Paris service.Donald, 1997, Daimler operated a total of six D.H.34s, four of which were leased from the

Air Council Air Council (or Air Force Council) was the governing body of the Royal Air Force until the merger of the Air Ministry with the other armed forces ministries to form the Ministry of Defence in 1964. It was succeeded by the Air Force Board. ...

, with

Instone Air Line Instone Air Line was an early British airline from 1919 to 1924. Along with other private airlines of the time, it was absorbed into Imperial Airways. This airline is not to be confused with Instone Air Line (1981) of Stansted, which operated ...

operating a further four, all leased. One aircraft was built to the order of the Soviet airline

Dobrolyot Dobrolyot, or sometimes Dobrolet (English: "good years"), was an early Soviet airline, with the name drawn from part of its full name (Добровольного or Dobrovol'nogo). The Russian Society of Voluntary Air Fleet (Российско� ...

. When Imperial Airways was formed on 1 April 1924, by the merger of Daimler Airway, Instone Air Line,

Handley Page Transport Handley Page Transport Ltd was an airline company founded in 1919, soon after the end of the First World War, by Frederick Handley Page. The company's first planes were Handley Page Type O/400 bombers modified for passenger use. They flew a Lo ...

and the British Marine Air Navigation Company, it inherited six D.H.34s, retaining the type in service until March 1926. The DH.34s were used heavily on the cross channel air services, with the fleet flying 8,000 hours in the first nine months of operation, and the second aircraft flying over without overhaul. Six D.H.34s were lost in accidents during the four years of their operation, of which several were fatal. In November 1923 an excellent air safety record for the "English Air Service" was broken by "a disaster in the London-Birmingham air route" when a DH.34 carrying only 3 passengers crashed near the Ivenhoe Beacon near

Leighton Buzzard Leighton Buzzard ( ) is a market town in Bedfordshire, England, in the southwest of the county and close to the Buckinghamshire border. It lies between Aylesbury, Tring, Luton/Dunstable and Milton Keynes, near the Chiltern Hills. It is northwe ...

where it was seen to be in difficulties before suddenly nose-diving at high speed into the ground killing all on board."Seats intact, but occupants smashed to a pulp", Sheffield Daily Telegraph, 15 Sept 1923, p7

Variants

;DH.34: Initial production version. 11 completed. ;DH.34B: Modication of DH.34 with extended upper wing to improve stalling characteristics.

Operators

; *

Accidents and incidents

* On 13 August 1923, G-EBBW of

landed at

Marden Airfield Marden Airfield was an airfield in Marden, Kent, United Kingdom. It was operation from 1917 to 1935. Initially a Royal Flying Corps airfield during the First World War it was used post-war as an Emergency Landing Strip, RAF Marden by the Royal A ...

due to a broken oil pipe. The aircraft was repaired and returned to

. * On 30 August 1923, G-EBBQ, the first registered DH.34, of

Daimler Hire Daimler Hire Limited provided a luxury chauffeur-driven Daimler limousine-hire-service from Knightsbridge in London. Incorporated in 1919 to take over the operations of Daimler's hire department, Daimler Hire was a subsidiary of Daimler Company. ...

on a flight to

Antwerp Antwerp (; nl, Antwerpen ; french: Anvers ; es, Amberes) is the largest city in Belgium by area at and the capital of Antwerp Province in the Flemish Region. With a population of 520,504,

, crashed at

Croydon Airport Croydon Airport (former ICAO code: EGCR) was the UK's only international airport during the interwar period. Located in Croydon, South London, England, it opened in 1920, built in a Neoclassical style, and was developed as Britain's main airp ...

and was written off. There were no casualties. * On 14 September 1923, G-EBBS of

crashed "Crashed" is the third U.S. rock Single (music), single, (the fifth overall), from the band Daughtry (band), Daughtry's debut album. It was released only to U.S. rock stations on September 5, 2007. Upon its release the song got adds at those stat ...

at Ivinghoe Beacon, Buckinghamshire whilst on a flight from Croydon to

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The ...

, Lancashire. * On 24 December 1924, G-EBBX of

crashed and caught fire shortly after take-off from Croydon, killing the pilot and all seven passengers.

Specifications (DH.34)

References

Citations

Bibliography

*Donald, David, ed. ''The Encyclopedia of World Aircraft''. London: Aerospace Publishing, 1997. . *Jackson, A.J. ''British Civil Aircraft since 1919 Volume 2''. London: Putnam,1973. .
"The D.H. Type 34 Commercial Biplane"
''Flight'', 5 January 1922, 3-View Drawing

''Flight'', 30 March 1922, further technical details * {{DEFAULTSORT:De Havilland Dh.34 Single-engined tractor aircraft Biplanes 1920s British airliners DH.034 Aircraft first flown in 1922