A.Jackson Avro Aircraft since 1908 (Putnam)
The Avro 510 was a large two seat, two bay seaplane built for the 1914 Circuit of Britain Race. A larger version of the 504 rudder proclaimed the aircraft's Avro origins but it bore no other resemblance to any previous machine built by the firm. The upper mainplane overhung the lower by more than 12 ft. and the extension planes (which carried the ailerons), were braced by cables to steel tube kingposts. Power was derived from a 150 h.p. Sunbeam eight cylinder watercooled engine (later named the Nubian), fitted with nose radiator and stub exhausts.
The undercarriage consisted of four steel struts connected at their lower extremities to a tubular steel rectangle, the corners of which were bolted to the attachment points of each float. These were of entirely new design with a pronounced taper aft of the single step. The tail was supported on a large wooden float with water rudder.
Built at Manchester in July 1914, the Avro 510 was despatched by rail to Calshot, starting point of the race. Following by road to supervise its erection, A. V. Roe put up for the night at Havant where the next morning he learned of England's declaration of war on Germany. The race was perforce cancelled but the Avro 510 was erected and flew well, the new float design being particularly successful. Much smoother landings were possible than with the old flat backed pontoon-type floats.
When the trials were complete, the machine was purchased by the Admiralty and much to A. V. Roe's surprise a cheque was handed over on the spot by Capt. (later Air Vice Marshal Sir Arthur) Longmore. The Admiralty also placed an order for five production Avro 510s but stipulated a taller undercarriage incorporating an extra inclined strut and using the well-tried, but entirely outmoded, flat backed floats. These were bolted direct to the struts without the complicated sub-frame of the original. To A. V. Roe's disappointment the modern floats of the prototype were also replaced.
R.N.A.S. Avro 510s were fitted with a fixed fin having a curved trailing edge which fitted snugly round the leading edge of the rudder. All six were based at Calshot and all were powered by the 150 h.p. Sunbeam. Data was published for a version with the 160 h.p. Gnome rotary but there is no evidence that this motor was ever fitted to an Avro 510. The Service history of the type is obscure but it is known that 130 was in service at Calshot until September 1917, and that 131 remained there in June 1916 while the remaining Avro 510s went to the Supermarine Works at Woolston for modification.
SPECIFICATION AND DATA
Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester
One 150 h.p. Sunbeam Nubian
One 160 h.p. Gnome
Span (upper) 63 ft. 0 in. (lower) 38 ft. 0 in.
Length (Sunbeam) 38 ft. 0 in. (Gnome) 37 ft. 6 in.
Wing area 564 sq. ft.
(Sunbeam) Tare weight 2,080 lb. All-up weight 2,800 lb.
(Gnome) Tare weight 2,005 lb. All-up weight 2,790 lb.
Maximum speed 70 m.p.h.
Climb to 1,000 ft. 44 minutes. Endurance 4 1/2 hours
Production: Prototype sold to the Admiralty 1914 and numbered 881; 130-134 built under Contract C.P.30654/14
M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
J.Bruce British Aeroplanes 1914-1918 (Putnam)
THE Avro 510 was a large and rather ungainly twin-float seaplane which was originally designed for the Daily Mail “Circuit of Britain” seaplane race of 1914. Owing to the outbreak of war the contest never took place, and it is quite probable that the original machine would be impressed for service with the R.N.A.S. At least five Avro 510s were built for the R.N.A.S. and were used for coastal patrol duties.
The prototype had a large balanced rudder, similar to but larger than that of the Avro 504, and each float was connected to the fuselage by two struts only: the floats of the prototype were built with a single step. The Service machines had a fixed fin added to the tail-unit: it had a curved trailing edge to match the leading edge of the rudder. The undercarriage of the later Avro 510s was noticeably taller than that of the prototype, and the rear attachment point of each float was joined to the fuselage by a vee strut. These floats were of the simple pontoon type, similar in appearance to those of the Short 184.
All the Avro 510s had the 150 h.p. Sunbeam engine, but exhausts varied. Twin stacks were used, each stack consisting of the four exhaust pipes from each bank of cylinders; but at least one machine had one single central exhaust stack.
There are references to a version of the Avro 510 powered by a 160 h.p. Gnome rotary engine, but it is uncertain whether it was ever built in that form. At least one Avro 510, No. 130, survived until September, 1917: it was at Calshot seaplane station until that date.
Manufacturers: A. V. Roe & Co., Ltd., Clifton Street, Miles Platting, Manchester; and at Hamble.
Power: 150 h.p. Sunbeam.
Dimensions: Span: upper 63 ft, lower 38 ft. Length: 38 ft. Chord: 6 ft. Gap: 6 ft 6 in.
Areas: Wings: 564 sq ft.
Weights: Empty: 2,080 lb. Loaded: 2,800 lb. (Corresponding figures quoted for version with 160 h.p. Gnome were 2,005 lb and 3,215 lb respectively.)
Performance: Maximum speed: 70 m.p.h. Climb to 1,000 ft: 4 1/2 min; to 3,000 ft: 15 min. Endurance: 4 1/2 hours. Service Use: R.N.A.S. Seaplane Station, Calshot.
Serial Numbers: 130-134, built under Contract No. C.P.30654/14.
P.Lewis British Aircraft 1809-1914 (Putnam)
Entry number 7 in the 1914 Daily Mail Circuit of Britain race for seaplanes was a comparatively large and rather clumsy-looking Avro biplane. F. P. Raynham was chosen to pilot the machine in the contest.
A Sunbeam engine of 150 h.p. was fitted, being fully enclosed in its cowling and given a large integral exhaust stack. The 63 ft. span upper wings possessed long tip extensions overhanging the 38 ft. lower wings, the cellules themselves being set at a fairly pronounced dihedral angle. The main floats were secured to the fuselage by a particularly strong strut system made to withstand the rigours of rough-water operation, with shock-absorbing by rubber cord. The prototype 510 did not embody a fin, having a balanced rudder only. A fin was fitted, however, to the production machines for the R.N.A.S., which used the 510 for patrol work from coastal air stations in 1914.
Description: Two-seat tractor biplane seaplane. Wooden structure, fabric covered.
Manufacturers: A. V. Roe & Co. Ltd., Clifton Street, Miles Platting, Manchester.
Power Plant: 150 h.p. Sunbeam.
Dimensions: Span, 63 ft. Length, 37 ft. 6 ins. Wing area, 564 sq. ft.
Weights: Empty, 2,080 lbs. Loaded, 2,800 lb.
Performance: Maximum speed, 70 m.p.h. Climb, 15 mins. to 3,000 ft. Endurance, 4.5 hrs.
O.Thetford British Naval Aircraft since 1912 (Putnam)
Two-seat patrol seaplane used by RNAS coastal air stations from 1914 at Dundee, Isle of Grain and Killingholme. Allotted Nos.130 to 134. One 150 hp Sunbeam Crusader engine and loaded weight of 2,800 lb. Maximum speed, 70 mph. Climb, 15 min to 3,000 ft. Endurance, 4 1/2 hr. Span, 63 ft. Length, 38 ft.
H.King Armament of British Aircraft (Putnam)
510. During 1915 a few two-seater floatplanes of this type were used by the RNAS for coastal patrol, but there appears to be no record of any armament which may have been carried.
Flight, September 18, 1914.
THE "ROUND BRITAIN" MACHINES.
THE machine which was numbered 7 in the Circuit of Britain, and for which Mr. F. P. Raynham had been nominated pilot, was
The Avro Seaplane.
No great departures from standard Avro practice are to be found in this machine except, of course, such alterations as have been necessitated by the substitution of a Sunbeam engine for the Gnome with which Avro biplanes have been usually equipped hitherto.
The fuselage is of the standard type, of rectangular section, and is built up of four longerons of ash connected by struts and cross members of ash and spruce. Three-ply wood stiffening pieces are screwed to the longerons, which by this means can be kept comparatively thin without sacrificing the necessary strength. The deck of the fuselage is in the form of a turtle back, whilst the bottom is flat. In front the fuselage is sufficiently deep to totally enclose the 150 h.p. Sunbeam engine, which is mounted on strong bearers suitably connected up to the lower longerons. The exhaust pipes are taken to a funnel projecting up above the upper main planes so that there is no danger of the exhaust gases causing pilot and passenger any discomfort, by being blown back in their faces.
The two seats, which are of the bucket type, are arranged in tandem, the pilot occupying the rear seat. Dual controls are fitted, so that either of the occupants may pilot the machine in turn. Ailerons and elevator are operated by means of rotatable hand wheels mounted on vertical columns, to which are connected the elevator control cables. Steering is effected by pivoted foot bars. Between the passenger's seat and the engine are arranged the petrol and oil tanks, which have a capacity of 52 galls., or sufficient for a flight of 4 1/2 hours' duration.
The main planes are of the usual Avro section, and are characterised by a very pronounced overhang of the top plane. Lift cables run to various points on these extensions from the lower ends of the outer inter-plane struts, whilst the top bracing wires are taken to king posts above the plane. Both upper and lower main planes are set at a very pronounced dihedral angle, thus helping to provide the necessary fin area to balance the side area of the floats. Ailerons are fitted to the top plane only, but as they are of large area, and the machine is, moreover, to a great extent inherently stable laterally, there is probably an ample amount of lateral control. Four pairs of spruce struts separate the main planes in addition to the two pairs of fuselage struts, and cable bracing provides the necessary rigidity.
Tail planes of the usual Avro type are fitted at the rear end of the fuselage. A flat, non-lifting stabilizing plane is bolted to the sides of the fuselage, to which it is further stayed by means of two struts running to the lower longerons. A divided elevator is hinged to the trailing edge of the stabilizing plane, and a balanced rudder pivots round the tubular extension of the stern post of the fuselage. The lower end of this tubular rudder post carries a small rudder used for steering when the machine is taxying on the surface of the sea. A flat-bottomed rectangular section float, supported on four steel tubes coming down from the lower longerons of the fuselage, takes the weight of the tail planes when at rest.
The main chassis is similar in type to that of previous Avro seaplanes, and is chiefly characteristic on account of the method of springing the floats. From the accompanying illustrations, it will be seen that the floats are supported on an "M"-form structure of steel tubes, as seen from in front. Transverse steel tubes connect the lower points of the M to provide lateral stiffness. Immediately above the floats the tubular chassis struts are bent downwards, and carry at their lower ends, which project down inside the floats, cross-pieces to which the shock-absorbers are attached.
The two main floats, which are pitched 9 ft. apart, are of rectangular section, and are provided with a single step, occurring approximately under the centre of pressure of the wings. They are very strongly built, and as they have not been unduly lightened (each of them weighs 200 lbs.), they may be relied upon to stand up to even a comparatively rough sea. The openings through which pass the chassis struts are covered with canvas flaps, forming a waterproof, and at the same time flexible, cover over the openings. Small wing tip floats are fitted to the lower plane under the outer pair of inter-plane struts.
The weight of the machine fully loaded, including pilot, passenger and fuel for 4 1/2 hours, is 2,800 lbs., and the loading works out at about 5 lbs. per sq. ft. A speed of 70 m.p.h. is anticipated.