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)
Eastbourne Aviation Company Circuit Seaplane
Entered as No. 5 in the 1914 Daily Mail Circuit of Britain contest for seaplanes, the Eastbourne Aviation Company's machine was an ambitious design which incorporated a 100 h.p. Green engine mounted inside the fuselage between the wings, driving a pair of 8 ft. 6 ins. diameter tractor propellers through inclined shafts and bevel gearing.
The head of the Company, F. B. Fowler, was scheduled to fly the big 54 ft. span seaplane in the event, which did not, however, take place owing to the outbreak of the 1914-18 War. The crew occupied side-by-side seats in the nose of the fuselage, which swept upwards towards the tail. The sides were flat, but curved deckings were added above and below, and the fuselage terminated in a rudder post, as sufficient side area was built, into the rear of the machine to enable a fixed fin to be dispensed with.
The wings were of parallel chord with three bays and no stagger. Ailerons were incorporated in the four wing-tips, and the lower wings were given dihedral while the upper planes were flat. The entire aeroplane was supported when on the water by a pair of long floats, which had one step towards the rear and which were set 12 ft. apart so that wing floats were unnecessary. The length of the main floats also rendered a tail-float superfluous, but the last bay in the fuselage contained a water-tight tank in case the tail should become immersed.
The principle of having the engine buried inside the fuselage, with either shaft or chain drive to outrigged propellers, was one which appealed to many designers for several years but which never proved to be fully satisfactory in practice. The struts which carried the propellers on the Circuit Seaplane were inclined to distort when full power was applied, and the machine, which was being modified when War broke out, was finally dismantled.
Description: Two-seat tractor biplane seaplane. Wooden structure, fabric covered.
Manufacturers: Eastbourne Aviation Co. Ltd., Eastbourne, Sussex.
Power Plant: 100 h.p. Green.
Dimensions: Span, 54 ft. Length, 31 ft. Wing area, 700 sq. ft.
Weights: Empty, 1,850 lb. Loaded, 2,809 lb.
Performance: Maximum speed, 65 m.p.h. Landing speed, 45 m.p.h. Endurance, 7 hrs.
Flight, September 4, 1914.
THE "ROUND BRITAIN" MACHINES.
THE machine officially numbered 5 in the Circuit of Britain, and which was to have been piloted by Mr. F. B. Fowler, was
The E.A.C. Tractor Seaplane.
This machine differs as a type from any of the other machines entered, in that it is a twin-tractor, fuselage biplane, although having its engine at the rear of the pilot. Constructionally the fuselage does not differ materially from usual practice, being built up of four ash longerons connected by struts and cross members of spruce, the whole braced with steel wire in the usual way. In shape, however, the fuselage deviates from standard types in that the longerons are swept upwards towards the rear in order to provide sufficient water clearance and thus dispense with the necessity of a tail float. In place of the latter member a safety tank is fitted inside the last bay of the fuselage. A good streamline is given to the fuselage by means of a turtle back and a rounded bottom, whilst the sides have been kept fiat, in order, probably, to provide the necessary vertical surface.
In the nose the fuselage is rounded to form a good entry for the air, and the turtle back is here swept up to form a wind screen in front of the occupants' seats. These are arranged side by side in a very roomy cockpit, and as they are practically on a level with the leading edge of the wings an exceptionally good view is obtained in a forward and downward direction, whilst the absence of any propeller draught, due to the mounting of the two propellers a considerable distance away from the fuselage, renders this machine as comfortable to fly as machines of the usual "pusher" type.
Behind the seats and inside the fuselage is situated the engine - a 100 h.p. Green - which drives the two tractors through two inclined shafts and bevel gears.
A special gear-box is attached to the engine, and the shafts, which are enclosed in torque tubes, run from here to other gearboxes bolted to the two interplane struts that carry the two tractors. Large petrol and oil tanks are provided inside the fuselage, and contain a supply sufficient for a flight of seven hours' duration, or 70 gallons of petrol and 6 gallons of oil.
The wings follow standard practice as regards their construction, and are characterised by having their trailing edge slightly longer than the leading edge, as shown in the accompanying plan view of the machine. The upper main plane is straight, whilst the lower one is set at a dihedral angle of 3° for the double purpose of increasing the lateral stability of the machine in flight, and to give adequate water clearance when on the surface of the sea. Eight pairs of spruce struts separate the main planes, and cable bracing is employed. Large ailerons are fitted to the outer portions of the trailing edge of upper and lower planes. Lateral control is by means of a rotatable hand wheel mounted on a vertical column in front of the pilot. As in practically all modern machines the ailerons are interconnected, so that when one is depressed the other is correspondingly elevated.
The tail planes consist of rudder, stabilizing plane, and elevator, whilst no vertical fixed surface is fitted, probably on account of the fact that the fuselage is comparatively deep at the rear and thus provides the necessary vertical surface. Should it be found desirable to fit vertical fins this may be easily accomplished, as the stern post of the fuselage is extended in both upward and downward directions. The fixed stabilizing plane, which is of roughly semi-circular shape, is attached to the sides of the fuselage, and is approximately in line with the propeller shafts. It is braced by steel tubes to the lower longerons. To the trailing edge is hinged the divided elevator.
The landing chassis consists of two long floats, each of which is carried on two pairs of struts, one pair running to the lower longerons of fuse/age and the other to the two interplane struts that carry the propellers. To add to the lateral rigidity of the whole structure stay wires are taken outwards to the interplane struts and inwards to the fuselage. As the floats are placed so far - 12 ft. - apart, it has been found unnecessary to fit any auxiliary floats to the wing tips. The floats themselves are 19 ft. long with a beam of 2 ft., and have a "Vee" bottom in front running into a flat bottom at the rear.
The weight of the machine empty is 1,850 lbs., and fully loaded 2,800 lbs., giving a loading of 4 lbs. per square foot. A maximum speed of 65 m.p.h. is anticipated, whilst it is hoped to bring the minimum speed down to about 45 m.p.h.
In view of the way in which this machine departs from what might be termed standard practice, its trials will be watched with the greatest interest.
Flight, December 11, 1914.
E.A.C. SEAPLANE FLOATS.
IN FIIGHT for September 4th last, full particulars were published with scale drawings of the Eastbourne Aviation Co.'s Circuit tractor seaplane. This machine, as our readers are aware, embodies several interesting features which, while to some extent to be regarded as innovations, cannot be viewed in any way as experiments, since they are the natural outcome of the experience of its sponsors, Mr. F. B. Fowler and Mr. F. Hucks, and of development.
During a recent visit to the company's works, opportunity was afforded of closely inspecting this seaplane, which is of exceptionally substantial construction.
Special attention has been given in the design to ensure the machine getting off the water even under adverse circumstances. Two factors tend to prevent a machine rising from the water, at all events in a seaway. The first is that as the aeroplane moves over the water, the floats, to some extent, endeavour to follow the natural formation of the surface; with the result that the tail, as it rises and falls, strikes the water and prevents the speed from rising sufficiently to allow the machine to get off. Much can be done to prevent the immersion of the tail by the use of a tail float, or perhaps better still, by using long floats of ample flotation; and it is the latter that are provided on the E.A.C., their length being no less than 19 ft. with a width of 2 ft. But in addition, the body, which is so capacious that three persons can sit comfortably within the cockpit, while another may be stowed at the side of the engine, is upswept to a marked degree, so that it resembles, in some ways, the appearance of a bird. This combination of long floats and upswept tail should enable the machine to be used in comparatively rough seas.
A seaplane is also occasionally prevented from getting away owing to the suction beneath the floats, and a system has therefore been devised to overcome this effect. Each of the floats, which are of particularly strong design, is divided into six compartments by one longitudinal and two athwartship bulkheads. On the under side of the floats are two steps, and the sides of the compartments are continued downwards, as shown in the accompanying sketch, so as to form a skirting, which, quite incidentally, prevents damage to the floats and keeps the machine level when it is standing upon the ground. At the front end of the float, near the upper surface, two pipes are inserted one on each side, which pass through the first athwartship bulkhead and have their other ends open at the commencement of the first step. The ends of these pipes are flanged and rivetted to the body of the float, and a joint is made between the piping and the bulkhead in order to prevent leakage should one compartment be punctured. Thus, as the seaplane travels over the surface of the water, air passes in through these pipes, effectively breaking the partial vacuum formed at the steps which tends to prevent the machine from leaving the surface.