P.4/34 PROTOTYPE: Hawker's answer to an Air Ministry request for a high-speed light bomber. The engine is a Rolls-Royce Merlin which, as will be noted, has the new type of combined glycol radiator, oil-cooler and air intake. New streamlined exhaust collectors are also incorporated. The cockpit enclosure is one of the neatest of its kind yet seen. Brooklands Track will be recognised below.
A fine shot of the Hawker Henley prototype K5115 with Brooklands mapped out below in 1937, note the sewage works on the port wing tip.
The first prototype Henley, K5115. Powered by a Rolls-Royce Merlin F, the aircraft made its first flight on March 10, 1937 from Brooklands.

The photograph emphasises the Henley’s corpulent profile and complex cockpit glazing. This aircraft was used as a Rolls-Royce Vulture testbed before being finally struck off charge on March 25, 1941.

This plan view of K5115 shows the Henley's similarity to the Hurricane: it utilised the fighter's outer wing panels and tailplane.

The photographs show Henley L3243, which underwent trials at Boscombe Down from November 1938 to August 1939. It was fitted with a 1,030 h.p. Merlin II engine, and was equipped for target towing.

L3276 with bombs mounted externally outboard of the undercarriage. The aircraft still handled well, though it was recommended that all bombs be dropped before landing.

K5115 caught by Flight’s photographer in 1937 with its flaps and undercarriage down.

Henley L3276 was powered by a Merlin V and underwent trials at A&AEE between February and March 1942, to gauge its performance with towing gear removed and with bombs carried externally. This aircraft had camouflaged upper surfaces and yellow underside, with black diagonal target tug stripes.

Another view of L3243, showing the target-towing gear.