RAE Hurricane
Encyclopedia
The RAE Hurricane was a single-seat, single-engined light monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
designed and built by the Aero Club of the Royal Aircraft Establishment
Royal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...
for the 1923 Lympne Motor Glider Competition
Lympne light aircraft trials
The Lympne Light Aircraft Trials were held to encourage the development of practical light aircraft for private ownership, with a strong but not exclusive emphasis on fuel economy. They were held in 1923, 1924 and 1926. Each year saw different restrictions on engine size, framed initially in terms...
. It was underpowered with an unreliable engine. Re-engined, it flew in many races, with first place in the 1926 Grosvenor Challenge Cup its greatest success.
Design and development
Amongst the many aircraft designed and built for the LympneLympne light aircraft trials
The Lympne Light Aircraft Trials were held to encourage the development of practical light aircraft for private ownership, with a strong but not exclusive emphasis on fuel economy. They were held in 1923, 1924 and 1926. Each year saw different restrictions on engine size, framed initially in terms...
light aircraft competitions of the mid 1920's, the RAE Hurricane and the Cranwell CLA.2 had one other thing in common. Both were product of amateur groups formed within government funded aeronautical establishments, the Royal Aircraft Establishment at Farnborough and the Cranwell RAF College
RAF Cranwell
RAF Cranwell is a Royal Air Force station in Lincolnshire close to the village of Cranwell, near Sleaford. It is currently commanded by Group Captain Dave Waddington...
. The Hurricane was built for speed and flew in the 1923 Lympne Motor Glider Competition
Lympne light aircraft trials
The Lympne Light Aircraft Trials were held to encourage the development of practical light aircraft for private ownership, with a strong but not exclusive emphasis on fuel economy. They were held in 1923, 1924 and 1926. Each year saw different restrictions on engine size, framed initially in terms...
, the CLA.2 for durability, flying in the two-seater competition the following year.
The Hurricane was a wooden framed, fabric covered shoulder wing monoplane. The wing was a two spar cantilever structure, made possible by the adoption of one of the novel thick Göttingen airfoil sections. It was tapered, but almost entirely on the trailing edge and with clipped wingtips. Seen in plan, the wing of the Hurricane looked much a late 20th century light aircraft. The competition rules required that aircraft could access suitable fields via a farm gate, and many met this condition with folding wings. The Hurricane's designer, Samuel Childs chose instead to make its wings easily detachable after removing eight bolts per side.
The fuselage of the Hurricane was in contrast very much of its time, built up on two upper longerons and a strongly curved keel, producing a structure that was narrow and almost parallel in plan and a thin triangle in cross section, deepest between engine and the wing leading edge, tapering rapidly aft. The single-seat open cockpit was at mid-chord, between the spars. The main undercarriage was a pair of fabric covered mtorcycle type wire wheels mounted at the ends of a horizontal leaf spring fixed to the keel and braced to the fuselage with a pair of V-struts, with the result that the Hurricane sat very close to the ground. At the rear the empennage was conventional, with a broad chord fin bearing an unbalanced rudder that extended between split elevators to the keel. Initially the tailplane leading edge was curved and merged into the curved elevator tips.
Forward of the wing, the fuselage tapered rapidly, mostly through the upward bend of the keel. Because the 600 cc Douglas flat twin engine used in the 1923 aircraft was geared down 2:1 via a front mounted chain drive that put the propeller shaft at the top of the motor, it was mounted low and to the rear of the nose, with cylinders exposed for cooling. The output of this engine was only 21.5 hp (16 kW).
Several changes were made during 1924. The Douglas engine was replaced with a 32 hp (24 kW) Bristol Cherub
Bristol Cherub
-See also:-Bibliography:* Guttery, T.E. The Shuttleworth Collection. London: Wm. Carling & Co, 1969. ISBN 901319-01-5* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....
II flat twin. This more powerful motor was also lighter, lacking the reduction gear of the Douglas and therefore mounted in the extreme nose with propeller and exposed cylinders at wing level. At about the same time the empennage was modified with a squarer tailplane, taller, less rounded fin and square tipped rudder. The leaf spring undercarriage was replaced with a lighter split axle unit carrying smaller wheels and braced with conspicuous V-struts to the wing roots. There were also modifications to the top of the fuselage, including the installation of a side hinged cockpit cover with an opening just large enough to allow the pilot's head to protrude.
Operational history
Only one Hurricane was built, registered G-EBHS. Since the Lympne trials were in October, the Hurricane must have made its first light in the late summer of 1923, probably piloted by Paul Bulman. At the trials, with Bulman at the controls it flew rather tail down, suggesting trim and wing incidence issues had not been sorted. Compared with some other competitors it was overweight; like many others it suffered from an unreliable engine. Worst, it was slow; it had been entered specifically for the Abdullah speed prize and there had been talk of speeds near 100 mph, but the best it could do was 58.5 mph (94 km/h) before retiring with a broken rocker arm. The winner of this £500 prize was the Parnall Pixie IIParnall Pixie
The Parnall Pixie was a low powered British single-seat monoplane light aircraft originally designed to compete in the Lympne, UK trials for motor-gliders in 1923, where it was successful...
at 76.1 mph.
As a single seater, the Hurricane did not qualify for the 1924 Lympne Two Seater Light Plane Competition
Lympne
Lympne is a village situated on the former sea cliffs above the Romney Marsh in Kent. It lies approximately west of Folkestone, 2 miles west of Hythe and east of Ashford....
, but flew in the Grosvenor Challenge Cup immediately afterwards, now powered with the Cherub engine. The extra power produced a speed of about 80 mph, but it failed at just past the half way stage. Its most successful meeting was at Lympne in August 1925, flown by F/Lt J. F. Chick where it won the light Plane Holiday Handicap, the Private Owners Race and, most prestigiously the eight lap, 100 mile (161 km) Grosvenor Challenge Cup, averaging 81.2 mph (131 km/h). In total, the Hurricane picked up £300 in prizes at that meeting. It was flown by Chick in its last Grosvenor Cup in 1926; although it was faster than before (84.8 mph or 136 km/h), it only managed third place. It was broken up later that year.