The RAF 3 was a British liquid-cooled, V-12 engine developed for aircraft use during World War I. Based on the eight–cylinder RAF 1 it was designed by the Royal Aircraft Factory but produced by the two British companies of Armstrong Whitworth and Napier & Son. First run in September 1914, a total of 289 were built.
The RAF 7 was a high compression version of the same engine.
First run in 1913, the RAF 1 was a British air-cooled, V-8 engine developed for aircraft use during World War I. Based on a French design it was designed by the Royal Aircraft Factory but built by six different British companies including Daimler, Rolls-Royce and Wolseley Motors Limited.
The RAF 1 was based on the Renault 70/80 hp engine, being intended specifically to replace that engine in the B.E.2c. It featured larger cylinders (3.9 in × 5.5 in (99 mm × 140 mm)) for a total displacement of 540 cubic inches (8.8 L). It was rated at 92 hp (70 kW) at 1,600 rpm. The heads were cast integrally with the cylinders, with the intake and exhaust valves set one above the other in an upside-down F-head configuration. The engines featured a large diameter lightweight flywheel at the rear, enclosed in a cast housing. Engine oil was picked up from the bottom of the crankcase and slung into a reservoir at the top. From there it was gravity fed, via a gallery high on the right side of the engine block, to the main bearing caps, and then to the connecting rod journals by centrifugal effect of the turning crankshaft. The main bearings were ball bearings and were splash fed. Engine oil from the gallery was also supplied to the 1 : 2 reduction gearbox at the front. This drove the four-bladed propeller at one half engine speed, and the single camshaft was splined into the rear of the short propeller shaft. This arrangement meant that no mechanical oil pump was needed. Excess engine oil from the flywheel overflowed the reservoir and trickled over the large surface area of the round flywheel cover. Two passages cast into the cover took air-fuel mixture from the carby mounted at the bottom to a copper U-shaped inlet manifold mounted between the banks of cylinders, and the flywheel cover acted as a heat exchanger, preheating the fuel-air. In late 1915, the bore was increased to 4.1 inches (100 mm), leading to an increased displacement of 590 cubic inches (9.7 L) and power of 86 kW (115 hp) at 1,800 rpm.
Built under licence by the Lanchester Motor Company Ltd in Birmingham, the RAF 1A is fitted with a Claudel-Hobson carburettor.
In late 1915 a supercharged experimental version of the RAF 1a was developed, the engine being flown in a B.E.2c improving the climb from taking 36 minutes to reach 8,500ft without the supercharger, to reaching 11,500ft in the same time.
The last aircraft type to emerge from the Royal Aircraft Factory at Farnborough, before its change of name in June 1918 to Royal Aircraft Establishment, the A.E.3 was itself an extrapolation from the N.E.1.
Designated as an “Armoured Experimental” type, the A.E.1 was intended as a specialised ground-attack fighter, for which purpose it was to mount a pair of 7.7mm Lewis guns in the nose, with a limited degree of movement in azimuth and depression. A third Lewis was to be pillar-mounted in the front, observer’s, cockpit for self-defence. Like the N.E.1, the A.E.3 was a large three-bay equi-span biplane, differing principally in the construction and shape of the nacelle, which was armoured with steel plate and provided stowage for 32 ammunition drums.
Intended to be powered by the 200hp Hispano engine as used in the N.E.1, the A.E.3 prototype emerged at the end of March 1918 with a 200hp Sunbeam Arab, whilst the second, eight weeks later, had a 230hp Bentley B.R.2 rotary. Flight testing of the latter began on 4 June, and larger ailerons and rudders were fitted before this A.E.3 went to France for service trials, which aroused little enthusiasm. The third aircraft, also completed in June 1918, had an Arab engine like the first and in this form the A.E.3 was named the Ram I, whilst the B.R.2 version became the Ram II.
A proposed derivative, the Ram III, was not built and no production ensued, other, better, types having become available.
AE.3 / Ram Mk. 1 Engine: 1 x 200-h.p. Sunbeam Arab Span: 47ft 10.5in Length: 8.44 m / 28 ft 8 in Height: 3.05 m / 10 ft 0 in Wing area: 52.02 sq.m / 559.94 sq ft Max. speed: 153 km/h / 95 mph Seats: 2
Ram Mk. II Engine: 1 x 230-h.p. Bentley B.R.2. Span: 47ft 10.5in Seats: 2
As a derivative of the F.E.9, the RAF planned to develop a dedicated night fighter as the F.E.12. This was to have used the same 200hp Hispano- Suiza eight-cylinder Vee-type water-cooled engine, the same undercarriage, tailbooms, tail unit and wing centre section as the F.E.9, and basically the same nacelle, but with the crew positions reversed. New equi-span, three-bay wings were planned, with plain unbalanced ailerons. The pilot, in the front cockpit for the best possible view during unaided nocturnal operations, was to have a forward-firing 7.7mm Lewis gun, whereas the observer was to be armed with a Vickers rocket gun for which two mounts were to be provided for firing forwards or aft. Provision was to be made for a searchlight in the nose, and another on the forward mount for the rocket gun, with a winddriven generator under the nacelle. Six prototypes were planned, but before construction began the designation was changed to N.E.1 (for “Night-flying Experimental”) and some changes were made. These eliminated the second searchlight, increased the span of the wing centre section, changed the tail unit design, moved the boom attachment points on the tailplane outwards, and introduced a wide-track undercarriage with a divided axle arrangement.
Flown early in September 1917, the first N.E.1 was almost immediately damaged and was then modified, before resuming flying on 4 October, to accommodate the observer in the front cockpit with the rocket gun and the pilot behind with a fixed Lewis gun. In this form, the N.E.1 was submitted to official trials at Martlesham Heath in November 1917, but was not thought to have adequate performance to serve as a night fighter. The other five prototypes were all completed by January 1918, but one was used only for static testing, another probably remained unflown and only one was issued to an RFC squadron for home defence.
Engine: 1 x 200-h.p. Hispano-Suiza Wingspan: 14.57 m / 47 ft 10 in Length: 9.19 m / 30 ft 2 in Height: 2.94 m / 10 ft 8 in Wing area: 51.57 sq.m / 555.09 sq ft Max take-off weight: 1336 kg / 2945 lb Empty weight: 939 kg / 2070 lb Max. speed: 153 km/h / 95 mph Ceiling: 5335 m / 17500 ft Seats: 2
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