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.


Design Company:

The de Havilland Aircraft Co. Ltd, Stag Lane Aerodrome, Middlesex

First Flight:

26 March 1922


11 - de Havilland

Type Specification

Applies to:

De Havilland D.H.34


Airliner based on unbuilt D.H.32 design


Two bay biplane. Equal span, unswept, unstaggered wings of fabric covered wooden construction with ailerons on all four wings


Box section fuselage with spruce longerons and wooden skin filling the interplane gap

Tail Unit:

Braced tailplane and elevators at top of fuselage with single fin and rudder

Landing Gear:

Crossaxle type attached by radius rod and oleo leg to fuselage lower longerons. Tail skid

Power Plant:

One 450 hp Napier Lion IB engine in nose driving two blade propeller


Crew of two in open cockpit ahead of wing with cabin between the wings for nine passengers



51 ft 4 in


39 ft


12 ft

Wing Area:

590 sq ft



4,574 lb


7,200 lb


Max Speed:

128 mph


365 miles