In 1934, the Air Ministry issued a specification for a light day-bomber also capable of providing close air-support. Accordingly, Hawker and Fairey submitted designs, the former offering a two-seat machine similar in size and general concept to its interceptor then in development (which would evolve into the Hurricane).
The outer wings and tailplane of both designs were built on identical jigs although the Hurricane’s eight-gun battery was deleted for the Henley, as the light-bomber was eventually named. The Henley's armament initially comprised a wing-mounted Vickers machine-gun and a Lewis gun in the rear cockpit.
The wing was set in a low mid-fuselage position, enabling the stowage of up to 550lb of bombs within the fuselage and with provision for another 200lb of bombs to be carried on underwing racks.
Construction of the Henley prototype (K5115) commenced at Hawker’s Kingston factory in mid-1935 and was powered by a Rolls-Royce Merlin engine. It made its first flight from Brooklands on 10th March 1937.
Initially it was flown with fabric-covered wings although it was later fitted with metal wings during August 1937. The design was of all-metal construction, with fabric-covered rear fuselage and tail similar to the Hurricane.
Showing a great deal of promise, the Henley was the subject of a production order for 350 with Gloster Aircraft at Hucclecote taking on construction duties.
A second prototype (K7554) was flown in May 1938 but a change in the Air Ministry’s policy on the role of the light day-bomber saw the Henley relegated to second-line duties, predominantly as a target-tug.
The aircraft (K7554) was then converted into the prototype Henley TT.III with a windmill device on the port side of the rear cockpit, used to reel in the drogue target.
The order was subsequently reduced to 200 with the type entering RAF service in November 1938.
Although a great improvement over the tired biplanes that it replaced in target-towing service, the Henley nevertheless struggled to maintain a steady towing speed of 220 m.p.h. (355km/h) without its Merlin engine overheating. It was thus found to be less than useful for the training of pilots in much faster fighters. As a result, the Henleys were sent to Anti-Aircraft Co-operation Units from late 1943 where they fared worse if anything, owing to the larger drogue targets they were then required to tow.
Having suffered an unusually high attrition rate throughout its career, the Henley was finally withdrawn from service altogether in April 1945.
The Henley was also used as an engine testbed, the original prototype (K5115) being fitted with a Rolls-Royce Vulture, 24-cylinder engine in 1939. The engine proved troublesome however and another example (L3302) was also similarly converted during the following year.
Additionally in 1940, a Henley (L3414) was fitted with a Rolls-Royce Griffon engine and was used for much of the trials work carried out on that engine for its further use in the Fairey Firefly.
The history of the Henley has always been the source of a certain amount of speculation and mystery. Questions were often raised about why the arguably much less capable Fairey Battle was selected to undertake certain duties when they would have been far better suited to the faster and more capable Henley.
Variants & Numbers
|Henley Mk I||First prototype K5115|
|Henley Mk II||Second prototype K7554|
|Henley Mk III||Production target-tug aircraft. 200 built|
|Total built||202 aircraft|
|Powerplant||One 1,030 hp Rolls-Royce Merlin II or III liquid-cooled engine|
|Capacity and armament||Two crew (pilot, and observer/gunner); unarmed in target tug role|
|Maximum speed||272 mph with air-to-air drogue at 17,500ft|
No examples of the Hawker Henley survive.