De Havilland
DH56 Hyena

An Army Co-operation biplane developed from the DH42B Dingo II.
De Havilland DH56 Hyena J7780 The first DH56 Hyena J7780 at Stag Lane, with 385hp Jaguar III engine.
The DH56 Hyena was prototype single-engine, two-bay biplane directly developed from the DH42A Dingo aircraft and was also intended for Army Cooperation duties.
It featured a number of changes including a lengthened nose, more rearward position for the pilot, internal fuselage fuel tank (rather than external wing-mounted tanks) and a lower wing of higher aspect ratio with a slightly reduced span.  
Carrying a crew of two, the DH56 was fitted with a forward firing Vickers machine gun and a Lewis gun operated by the Observer. It also featured a hook mounted beneath to pick up messages as well as mountings for photography, artillery spotting, supply dropping and bombing.   
The first aircraft (J7780) flew at Stag Lane on 17th May 1925, powered by a 385 hp Jaguar III radial engine although this was found to be significantly under-powered. After suffering an engine failure at Hendon, the prototype was fitted with a 422 hp Jaguar IV engine.
Trials at Martlesham Heath against Specification 30/24 (for which the Armstrong Whitworth Atlas was ultimately selected) revealed generally pleasant handling but inadequate performance against the requirement.  The pilot’s field of view was also criticised in Service Trials.
The second prototype (J7781) also made use of the Jaguar IV and was flown for the first time on 29th June 1926.
There was no further production and this aircraft, like the earlier 'Dingo II', ended its career on experimental flying at RAE Farnborough.


Powerplant                         One 385 hp Armstrong Siddeley Jaguar III or 422 hp Jaguar IV fourteen cylinder engine
Span 43 ft 0 in
Maximum Weight  4,200 lb
Capacity Pilot and observer positions; provisions for 4 bombs under port wing. Forward firing synchronised Vickers machine gun and single Scarff-mounted Lewis gun for self-defence.
Maximum Speed 130 mph; 122 mph at 10,000 ft

Numbers Built

Number built                       Two only: J7780 and J7781