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de
Havilland DH 34
Building on commercial experience obtained
with the D.H.18 and structural experience with the D.H.29, de Havilland
began work on a new type, the de Havilland D.H.32, in 1921. Considerable
progress had been made, and plans for construction of the first aircraft
(with the 360 hp/268 kW Rolls-Royce Eagle engine as its powerplant) had
been announced. The new design showed great promise, but since the main
customers would be Instone and Daimler Hire, who were already using Napier
Lion powered D.H.18s, de Havilland bowed to their wishes and redesigned
the aircraft to use that engine. The result was the de Havilland D.H.34,
the company's most successful aircraft of the early post-war period.
The first of 11 aircraft flew in March 1922, and made an inaugural Croydon-Paris
flight on the 2nd April. Daimler Hire eventually used six D.H.34s and
Instone four, while one was sold to Dobrolet, the Russian airline. When
Imperial Airways was formed in 1924 it took over seven D.H.34s and used
them over the next two years before deciding to re-equip with larger
aircraft.
There can be no doubt that the D.H.34s made an impressive mark on the air
transport scene during the four years or so in which they served. Some
8,000 hours were recorded by December 1922, less than nine months after
the prototype's appearance, and over 100,000 miles (160,934 km) flown
without overhaul by the second Daimler aircraft. However, no less than six
D.H.34s were lost in accidents, several of them fatal. An early stalling
crash led to extensions being added to the top wing to increase its area,
giving rise to the designation D.H.34B. The last four D.H.34s in UK
service were scrapped in 1926.
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Design
Company: |
The de
Havilland Aircraft Co. Ltd, Stag Lane Aerodrome, Middlesex |
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First
Flight: |
26 March 1922 |
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D.H.34: |
11 - de
Havilland |
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Type
Specification |
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Applies
to: |
De Havilland
D.H.34 |
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Type: |
Airliner
based on unbuilt D.H.32 design |
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Wing: |
Two bay
biplane. Equal span, unswept, unstaggered wings of fabric covered wooden
construction with ailerons on all four wings |
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Fuselage: |
Box section
fuselage with spruce longerons and wooden skin filling the interplane
gap |
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Tail
Unit: |
Braced
tailplane and elevators at top of fuselage with single fin and rudder
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Landing
Gear: |
Crossaxle
type attached by radius rod and oleo leg to fuselage lower longerons.
Tail skid |
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Power
Plant: |
One 450 hp
Napier Lion IB engine in nose driving two blade propeller |
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Accommodation: |
Crew of two
in open cockpit ahead of wing with cabin between the wings for nine
passengers |
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Dimensions |
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Span: |
51 ft 4 in |
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Length: |
39 ft |
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Height: |
12 ft |
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Wing
Area: |
590 sq ft |
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Weights |
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Tare: |
4,574 lb |
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All-up: |
7,200 lb |
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Performance |
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Max
Speed: |
128 mph |
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Range: |
365 miles |
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