In 1922, the Air Ministry issued Specification 37/22, calling for a three-seat fleet reconnaissance aircraft for the Royal Navy. Several aircraft manufacturers responded including H.G. Hawker Engineering Company who began work in 1923, on what would become the sole Hawker Hedgehog.
Powered by a single 398 hp Bristol Jupiter IV nine-cylinder radial engine, the Hawker Hedgehog was a single-bay unstaggered biplane of equal span and chord (distance between the wing’s leading and trailing edges) with dihedral on the outer sections. It was of conventional, fabric-covered wooden construction, and designed to accommodate the pilot, observer and air gunner in separate tandem cockpits. These were positioned directly beneath, and to the rear of, the upper wing. It featured folding wings for ease of storage and for carrier operations.
The Hawker Hedgehog made its first flight in February 1924 at Brooklands, in the hands of test pilot F.P. Raynham, wearing B Conditions marking T-2.
The Hawker Hedgehog underwent extensive trials until late August of that year, when it was sent to the Aeroplane & Armament Experimental Establishment (A&AEE) at Martlesham Heath for Service evaluation trials.
The A&AEE pilots found the Hawker Hedgehog to be 'exceptionally light and pleasant to handle in the air' and it was reported that it was 'entirely satisfactory and eminently suitable for its prospective role'.
In February 1925, the Air Ministry purchased the sole example Hawker Hedgehog. It had been built by H.G. Hawker Engineering Company as a private venture so it given a Royal Navy serial (N187). By this time, however, the original specification had been cancelled, as the Air Ministry considered none of the aircraft tested represented a sufficient advance over any of its existing, contemporary types.
The aircraft was returned to Martlesham Heath for further trials, most notably for research into its unusual drooping ailerons. It appeared in the New Types Park (wearing the number '4') at the RAF Display at Hendon, in June 1925. It was then converted to a floatplane and tested by the Marine Aircraft Experimental Establishment (MAEE) at Felixstowe that summer.
Once converted back to landplane configuration, it was used for deck-landing trials aboard HMS Argus during September 1925, before being fitted with a 450 hp Jupiter VI engine the following year, and subsequently receiving the designation Hawker Hedgehog II.
By December 1926, the Hawker Hedgehog was back at the A&AEE before moving onto the Royal Aircraft Establishment (RAE) at Farnborough during the spring of 1927.
Its ultimate fate is unclear although it is known that it suffered an accident in which it tipped on to its nose during landing on 9th May 1927. This may well have been the end of its flying career as there appears to be little or no information on when it was officially withdrawn from service and scrapped.
Variants & Numbers
One aircraft only, N187, flown flown both as a landplane and a seaplane.
|Powerplant||One 398 hp Bristol Jupiter IV nine-cylinder radial engine driving a two-bladed wooden propeller; One 450 hp Bristol Jupiter VI (Hedgehog II)|
|Maximum weight||4,791 lb normal, 4,800 lb overload|
|Capacity & Armament||Three crew: pilot, observer, air gunner; One forward-firing Vickers gun and one Lewis gun on gunner’s Scarff ring|
|Maximum speed||120 mph at sea level|
The sole Hawker Hedgehog is believed to have been written off after an accident whilst being tested as a seaplane.