De Havilland

DH27 Derby

The De Havilland Aircraft Company DH27 'Derby' was a large, single engine, two-bay biplane designed to Air Ministry Specification 2/20. Two prototypes (J6894 & J6895) were built and powered by the 650 hp Rolls-Royce Condor engine and the type was intended for service as a long-range heavy day bomber.

 

Although the design was initiated by The aircraft Manufacturing Company (Airco), it was eventually completed by the newly-formed De Havilland Aircraft Co Ltd and it became their first military aircraft design.

 

Apart from its large size, the type was easily distinguished by a fully-faired centre-section, containing the 212 gallon fuel tank and eliminating the normal centre-section struts.  Given its large wingspan of more than 64 ft, it is not surprising that a 'folding-wing' arrangement was provided to make hangarage more efficient. 

 

 

The air crew comprised pilot and gunner, who were seated high-up in open cockpits, whilst the navigator / bomb aimer sat in an enclosed cabin with three portholes on each side.

 

The prototype (J6894) flew for the first time on 13th October 1922 at Stag Lane, with the second aircraft following on 22nd March 1923.

 

Unfortunately for De Havilland, the Avro Aldershot (designed to the same specification) offered better performance than the all-wooden De Havilland DH27.  The Avro Aldershot was not only lighter and had a better overall performance, it also carried its bombload internally. Consequently, it was the Avro design that was chosen for RAF service in January 1923.

 

Thereafter, the two De Havilland DH27 prototypes were moved to the Aeroplane and Armament Experimental Establishment (A&AEE) at Martlesham Heath and then onto the Isle of Grain Naval Station, although they were little used other than for occasional testing.