The Hawker Henley was designed as a light bomber, and was closely related to the Hawker Hurricane. It had been designed by Hawker in response to Air Ministry Specification P.4/34 of February 1934 for a light bomber and close support aircraft, with high performance and a low bomb load.
The resulting aircraft was very similar in appearance to the Hurricane, sharing most of the wing and the tail plane with that aircraft. The main difference between the two types was the cockpit, designed to carry a two man crew – pilot and observer/ air gunner.
Work on the Henley progressed slowly. The prototype took two years to complete, finally taking to the air on 10 March 1937. The Henley performed well in tests, but three years after issuing the initial specification the air ministry decided it no longer needed a new light bomber. However rather than cancel the Henley it was decided to use the aircraft as a target tug. Somewhat ironically the Hawker Hurricane would later go on to perform a role very similar to that originally intended for the Henley, acting as a ground attack aircraft.
The Henley was not a great success as a target tug. The first modified Henley TT.III flew on 26 May 1938, and an order was placed for 200. In service it was discovered that the Merlin engine could not cope with high speed target towing. After a brief period towing large drogue targets, the Henley was retired in May 1942, in favour of the Boulton Paul Defiant, which was itself obsolescent as a front line aircraft (the Henley had also been developed into a turret, the Hawker Hotspur, but that never passed the prototype stage).
Stats at target tug
Engine: Rolls Royce Merlin II or III
Max speed: 272 mph with air-to-air target; 200mph with air-to-ground target
Range: 950 miles
Span: 47ft 10.5in
Length: 36 ft 5in