A.Jackson Avro Aircraft since 1908 (Putnam)
The Avro 508 was a two seat reconnaissance biplane built at the Manchester works in December 1913 and delivered at Brooklands for erection and test a month later. Following contemporary practice it was a twin boom, three bay pusher biplane of fabric covered wooden construction having equal span mainplanes structurally similar to those of the Avro 504 prototype. A wide centre section carried the first pair of interplane struts at its extremities, the dihedral commencing at this point as on the Avro 503. Ailerons were used for lateral control and the machine was noteworthy as the first Avro type to have aileron cables located inside the wing leading edge and running over buried pulleys.
A capacious square-section nacelle, built up from four ash longerons and spruce cross struts, accommodated two crew in tandem. The observer/gunner sat in the nose for maximum field of vision with the pilot behind. Fuel and oil tanks were located behind the pilot's seat and just ahead of an 80 h.p. Gnome rotary engine mounted on steel tube bearers. The use of standard Avro cowlings and centre skid undercarriage heightened its likeness to a back-to-front Avro 504. Tail booms were of steel tubing braced by streamline section spruce struts, the rear extremities of which were built into the tailplane structure. For ease of dismantling, the booms were jointed just ahead of the tailplane leading edge. The rudder was an elongated version of the famous comma type, somewhat like an artist's palette.
The Avro 508 was not adopted for the Royal Flying Corps and the single machine built made but two public appearances. The airframe was shown without covering at an exhibition at Belle Vue Gardens, Manchester on January 1-3, 1914 and the complete aircraft was shown on the Avro stand at the Olympia Aero Show, London on March 16-25,1914.
SPECIFICATION AND DATA
Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
Power Plant: One 80 h.p. Gnome
Span 44 ft. 0 in. Length 26 ft. 9 in.
Height 10 ft. 0 in. Wing area 468 sq. ft.
Weights: Tare weight 1,000 lb. All-up weight 1,680 lb.
Performance: Maximum speed 65 m.p.h. Endurance 4 1/2 hours
M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
P.Lewis British Aircraft 1809-1914 (Putnam)
The Avro 508 Military Biplane was a two-seat pusher fighter which was exhibited at the 1914 Olympia Aero Show. The machine was fitted with the Avro Safety-belt and was powered with the 80 h.p. Gnome. Span, 44 ft. Length, 26 ft. 9 ins. Wing area, 468 sq. ft. Weight empty, 1,000 lb. Weight loaded, 1,800 lb. Maximum speed, 65 m.p.h. Landing speed, 35 m.p.h. Endurance, 4.5 hrs.
H.King Armament of British Aircraft (Putnam)
508. This pusher biplane is given precedence over the armed 504s by reason of the fact that it was built before the outbreak of war specifically to carry a gun. To quote from the catalogue of the Aero and Marine Exhibition held at Olympia in March 1914:
'The 1914 Type Two-seater Gun-carrying Push Machine (sic) is a new model and embodies many novel features and advanced ideas . . . The observer or gunner is seated in the front of the machine, thus giving him a clear range of vision.'
F.Mason The British Fighter since 1912 (Putnam)
Avro Type 508
One of several companies which tried their hand at gun-carrier biplanes in the two years before the War was A V Roe & Co Ltd, a manufacturer that had made long strides since its founder, the pioneering pilot-designer Alliott Verdon Roe, had taken his first faltering steps into the air on 8 June 1908 at Brooklands. By the time the Avro 508 was produced in December 1913 the company had already launched the Type 504 - the most widely used trainer flown in Britain during the First World War.
The Type 508 was a two-seat, three-bay pusher biplane whose square-section nacelle was constructed of ash longerons and spruce struts and was fabric-covered; it accommodated an observer-gunner in the nose and the pilot amidships, forward of the fuel tank. At the rear, carried on steel tubular bearers, the 80hp Gnome rotary drove a two-blade pusher propeller. Ailerons were fitted on both upper and lower wings.
The aircraft was exhibited in an in complete state at Belle Vue Gardens, Manchester, on New Year’s Day, 1914, and the following month appeared in its finished state on the Avro stand at the Olympia Aero Show in London.
The Avro 508 won no production order, probably on account of being somewhat underpowered. Indeed it is not known for certain whether the single example was ever flown.
Type: Single pusher engine, two-seat three-bay gun carrier biplane.
Manufacturer: A V Roe & Co Ltd, Miles Platting, Manchester, and Brooklands, Surrey
Powerplant: One 80hp Gnome rotary air-cooled engine driving two-blade pusher propeller.
Structure: Wings and nacelle constructed in wood with fabric covering; steel tubular engine bearers. Twin-wheel and single-skid undercarriage.
Dimensions: Span, 44ft 0in; length, 26ft 9in; height, 10ft 0in; wing area, 468 sq ft.
Weights: Tare, 1,000lb; all-up, 1,680lb.
Performance: Max speed, 65 mph at sea level; endurance, 4 1/2 hr.
Armament: Provision intended for a single machine gun on nose of nacelle.
Prototype: One (possibly not flown); no production.
Flight, March 14, 1914.
WHAT THERE WILL BE TO SEE AT OLYMPIA.
Avro (A. V. Roe and Co.). (64.).
THIS well-known firm will exhibit three machines, all of which are fitted with 80 h.p. Gnome engines - a tractor hydro-aeroplane, a fighting biplane, and a scout tractor.
The fighting biplane is a land machine of the "pusher" type, and has been recently introduced. The observer, or gunner, is seated well in front of the machine so as to give a wide range of vision for observation purposes, while sufficient fuel may be carried to last for 4 1/2 hours' continuous flight. The engine is encased in a streamline casing, as is also that on the former machine, and is supported in bearings fore and aft so as to obtain greater rigidity and avoid the use of an overhung engine.
Each of the above machines will be fitted with the Avro safety belt, concerning which there is ample evidence of the fact that it has been designed by a practical man. Its notable features are, that the aviator gets into and out of the belt by means of the quick-release devices, which are in duplicate - one on each side - thereby ensuring that it is in working order, and the ample depth of the front section of the belt, which precludes any possibility of internal injury resulting should the pilot be suddenly thrown forward.
Flight, March 21, 1914.
THE OLYMPIA EXHIBITION.
AVRO (A. V. ROE AND CO.). (64.)
THREE machines of different types, all representing considerable departures in design from previous models, whilst at the same time retaining the good qualities that have established such an enviable reputation for this enterprising firm. Keenly alive to the various requirements of the Army and Navy, Mr. A. V. Roe has designed three entirely different types, each for a different purpose, one being a military biplane of the pusher type, and built with a view to meeting the demand for a machine affording the observer an unrestricted view, and also possessing facilities for the mounting of a gun if desired. The second machine is a small, fast, single-seater, designed for scouting purposes, whilst the third and last is a hydro-biplane. All three machines are fitted with 80 h.p. Gnome engines.
The 80-h.p. Military Biplane is of more or less standard design for this type of machine, as regards the general disposition of its component parts, but its designer has managed to incorporate in it numerous detail innovations. The nacelle, which is very wide and deep, is built up in the usual way of four ash longerons, connected by struts and cross members of spruce, strengthened in places by steel tubes. Inside this nacelle are arranged the pilot's and passenger's seats, tandem fashion, the pilot occupying the rear seat, so that the observer has a clear view, while it is possible to have a gun mounted on the nose of the nacelle. The controls are of the usual Avro type, consisting of a vertical lever mounted on a transverse rocking shaft, from which cables are taken to the various control organs. The ailerons are operated by a tide-to side movement of the lever, while a to-and-fro movement actuates the elevator. A pivoted foot-bar controls the rudder.
Behind the pilot's seat, and just in front of the engine, are the petrol and oil tanks, which have a capacity sufficient for a continuous flight of 4 1/2 hours. The engine, which is mounted on double bearings in the rear of the nacelle, is almost entirely covered in by an aluminium shield secured to four tubular extensions of the nacelle longerons. At their rear extremities where they converge, these extensions carry one of the engine bearers, the other being formed by a pressed steel frame mounted on the nacelle proper.
For a machine of the pusher type the chassis is rather unusual, it being in fact exactly similar to the chassis fitted to the Avro tractor machines. It consists of a single central ash skid carried on two pairs of steel tube struts, and two wheels sprung in the usual way by means of rubber shock absorbers attached to the T pieces of the wheel struts. In order to diminish head resistance, the shock absorbers have been enclosed in streamline aluminium casings.
The tail planes are similar to those of the tractor machines, the mounting of the fixed tail plane, however, being rather unusual, for the tail plane is not mounted on top of the tail booms, as is usually the case, but encloses the rear portion of the booms. In order to facilitate dismantling, the portion of the tail booms which is enclosed by the tail plane, is hinged to the remainder of the tail booms by a joint immediately in front of the tail plane, and the necessary rigidity at this point is obtained by cable bracing to the rudder post.
The main planes are of standard Avro type, except that the dihedral angle does not extend throughout the whole length of the planes, the central portion out to the first pair of struts being straight, so that only the outer portion of the wings are set at a dihedral angle. The method of carrying the aileron cables to the crank levers is rather unusual, and is illustrated by one of the accompanying sketches. It will be seen that the pulley has been placed inside instead of on top of the wing, the cable passing through a small opening in the lower surface of the wing.
Common to all the three machines is an extremely neat instrument board of Avro design, comprising altimeter, clock, compass, air speed indicator and revolution indicator, and all the machines are furthermore fitted with the Avro safety belt, the design of which is already known to the majority of our readers.