M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)

P.Lewis British Aircraft 1809-1914 (Putnam)

Dunne D.8 and D.10

   Lt. J. W. Dunne's final designs for the Blair Atholl Aeroplane Syndicate reverted to the biplane form in his D.8 and D.10 two-seaters built by Short Brothers at Leysdown, Isle of Sheppey, Kent, during 1911-12.
   The D.8 was a single-engined conversion of the crashed D.5 of 1909-10, and used the same wings of 45 ft. span, with a chord of 6 ft. and a similar sweepback angle of 30°. The wing-tips were enclosed by fixed vertical fins, the flying controls consisting of split ailerons extending across the trailing-edges of the two outermost bays on the four planes. They were operated independently of each other as rudders for turning, or they could be employed as elevators using both flap sections on each side in unison for "up" or "down". The wings of the D.8 demonstrated in a pronounced way the Dunne method of obtaining stability by changing the camber of the wing section continuously across the span from the leading-edge at the roots to the trailing-edge at the tips.
   The nacelle was mounted between the lower wings, the pilot sitting at the front, with his passenger towards the rear and just ahead of the fuel tanks. Both flyers could handle the machine, as dual control levers were installed. The undercarriage was a fairly complex but successful unit designed specially to allow the D.8 to operate without fear of damage from the comparatively rough aerodromes in use. The front strut system and sprung skid were of wood, while the rear sprung chassis carrying the twin wheels was composed of steel tubing. Long sprung skids supported the tips of the wings on the ground.
   In the D.8, twin propellers were abandoned in favour of the simplicity of a single one, 8 ft. 2 ins. in diameter, driven direct by a 50 h.p. Gnome engine at the rear of the nacelle. On 18th June, 1912, the D.8 was used at Eastchurch by Capt. A. D. Carden, who possessed one hand only, to gain his Royal Aero Club Aviator's Certificate No. 239. The machine was flown by N. S. Percival from the summer of 1912 until 1913. Early in 1913, the French Astra Company had shown sufficient interest in producing the machine in France to send their pilot Mons. Montmain over to lest it. However, the project lost its appeal for Astra, and the firm of Nieuport sent Commandant Felix to assess the D.8 for them at Eastchurch. During 11th and 12th August he flew it from Eastchurch to Villacoublay, and demonstrated it during the same month before the French Aeronautic Corps. Felix took the D.8 to a week's flying meeting being held at Deauville, where he astonished the spectators by leaving the cockpit while flying solo and walking out on to the lower wings. Another highlight of his tour with the machine was his flight in it over Paris on 20th August, 1913, and at the 1913 Paris Aero Show a version built by Nieuport was on display with a simplified landing-gear.
   The D. 10 was another two-seater built during 1912. It was fitted with an 80 h.p. Gnome and was converted later to a D.8. The span was 45 ft., with a wing area of 448 sq. ft. and a loaded weight of 2,202 lb. Maximum speed was 50 m.p.h., a drop of 5 m.p.h. from the 55 m.p.h. of the first D.8, which was brought about by the increase of weight. After the conversion, Percival flew the second D.8 to pass its War Office tests successfully, the machine proving to be the best of the series. The result was that an order for two for the R.F.C. was placed during March, 1913, one being constructed at Eastchurch, with the other being built at Flendon. Both were reported as overdue in delivery during the following August, and were still being completed in September, 1913.
   Another version of the D.8, with a 60 h.p. Green engine, was produced during 1913; in this the loaded weight was increased from the 1,900 lb. of the original D.8 to 2.1 14 lb., the span of 46 ft. and the wing area of 552 sq. ft. remaining the same.
   The American Burgess Company built three Burgess-Dunne single-float seaplane variants. These were the two-seat BD with a 100 h.p. Curtiss OXX2 engine, a span of 46 ft. and a top speed of 69 m.p.h., the BDH two-seater powered by a 140 h.p. engine, with a span of 46.6 ft. and a maximum speed of 70 m.p.h., and the BDI, which was a single-seater. A three-seat flying-boat was constructed by Burgess during 1916 and was designated the BDF. A 100 h.p. Curtiss OXX2 provided the power for the 53 ft. span machine, which had a top speed of 68 m.p.h.

SPECIFICATION (D.8)

   Description: Two-seat tailless pusher biplane. Wooden structure, fabric covered.
   Manufacturers: Short Brothers, Leysdown, Isle of Sheppey, Kent.
   Power Plant: 50 h.p. Gnome, 60 h.p. Green, 80 h.p. Gnome.
   Dimensions: Span, 46 ft. Wing area, 545 sq. ft.
   Weights: Empty, 1,400 1b. Loaded, 1,900 lb.
   Performance: Maximum speed, 55 m.p.h.

L.Opdyke French Aeroplanes Before the Great War (Schiffer)

Jane's All The World Aircraft 1913

DUNNE. The Blair Atholl Aeroplane Syndicate, Ltd., 1, Queen Victoria Street, London, E.C. School: Eastchurch. In 1906 Lieut. Dunne was employed by the British Army authorities for secret aeroplane experiments. He had at that time patented a monoplane of arrow type. In 1907 Dunne I was tried on the Duke of Atholl's estate in Scotland, but failed to fly, being smashed on the starting apparatus. Dunne III, a glider, 1908, was experimented with successfully by Lieut. Gibbs. In the same year Dunne IV, a larger power driven edition made hops of 50 yards or so. Early in 1910 the War Office abandoned the experiments. Dunne II, a triplane of 1906 design, was, by consent of the War Office, assigned to Prof. Huntingdon, who made one or two short flights with it at Sastchurch in 1910. At the same time the above syndicate was formed, and Dunne V, built by Short Bros., was completed in June, 1910. In 1912-13 the Huntingdon, modified, was flying well.

   50 Gnome.
   1912-13 1912-13 1912-13 1912-13
   Model and Date. single-seat 2-seater biplane biplane
   mono. mono D8. D9.
   D7. D7<i>bis.</i>
-------------------------------------------------------------------------------
Length........feet(m.) <i>not given</i> ... ... ...
Span..........feet(m.) 35 (10.66) 85 (10.66) 46 (14) 45 (13.70)
Area......sq.feet(m?.) 200 (18.5) 200 (18.5) 552 (51) 448 (42)
Weight, total,
............lbs.(kgs.) 1050 (476) 1200 (544) 1700 (774) 1693 (768)
Weight, useful
............lbs.(kgs.) 359 (161) 528 (230) 414 (187) 509 (231)
Motor.............h.p. 50 Gnome 70 Gnome 60 Green 80 Gnome
Speed......m.p.h.(km.) 60 (95) 60 (95) 45 (70) 50 (80)
Number built during 1912 1 1 1 5
   building
   ('13)

Notes.--Biplane D 8 is identical with the original pattern Dunne V, except that it has only one propeller instead of two. It has been flown completely uncontrolled in a 20 m.p.h. wind, carrying a R.Ae.C. observer as passenger.

Журнал Flight

Flight, June 22, 1912.

THE DUNNE MACHINES IN FLIGHT.

   WE publish this week, two or three photographs taken by Miss Dunne of her brother's machines at the Royal Aero Club's Eastchurch flying grounds. Everyone will rejoice to hear that Mr. Durme has recovered from his very serious illness, and is now back at work again. Not only is Mr. Dunne himself flying at Eastchurch, but Capt. Carden, R.E., as our readers know, has been making the best sort of progress, passing for his brevet last week, and Capt. Carden, as some of our readers may not know, has the misfortune to have lost an arm, wherefore his practice with the Dunne machine is worthy of very special attention.
   Two of the photographs show the biplane in flight, and both illustrate very clearly the V plan of the wings, from which, in conjunction with the peculiar variation in camber from shoulder to tip, is derived the high degree of natural stability that this flyer has always claimed to possess. It has flaps at the extremities of the main planes, but these are for the purpose of steering and elevation only; they are independently operated by separate levers, one on each side of the pilot, which adds to the significance of Capt. Carden's performances.
   The monoplane, which is illustrated with Mr. Dunne in the pilot's seat, is built on the same principle as the biplane, but the absence of the lower plane gives it a very extraordinary appearance. We have heard other pilots describe the flying of this machine as revolutionary, and certainly it may be taken for granted that the Astra Co. of France would not have taken up the French rights and be making preparations for building these machines in their own country if they did not think a great deal of them. In the early days of motor cars, it will be remembered, all the good things came from France in the first instance, but the tide turned at last. Let us hope that it may do so in aviation, and long may men like J. W. Dunne, who are devoting the best of their lives to the cause, be spared fully to achieve the ends they have in view.


Flight, November 15, 1913.

THE DUNNE BIPLANE.

   AT the present time there may be said to be two general types of aeroplanes which have been designed with a view to obtaining inherent automatic stability. One type has been developed in Austria and Germany by Herr Etrich and in this country by Mr. Handley Page, and the other is the Dunne type here described. As the theory of the Dunne machines has already been fully explained in the columns of FLIGHT (June 18th and 25th, 1910), we need not here enlarge upon that subject, but can confine ourselves to a description of the practical construction of the machine. We should like, however, to point out the most essential difference between the Etrich-Handley Page type and the Dunne. In the former stability is obtained by having the trailing edge of the back swept wing tips raised, thus setting these at a negative angle of incidence, whilst in the Dunne the leading edge of the wings are given a negative dihedral angle in order to obtain a negative angle of incidence on the wing tips. Another point in which the Dunne differs very considerably from the other types is that whilst these have tail planes of the ordinary type the Dunne machines have no tail planes, or, more correctly speaking, the back swept main planes perform the duty of the usual tail planes, in so far as they serve as both rudder and elevator.
   From the plan view of the machine it will be seen that the main planes slope backwards very considerably, 14 ft. to be exact. Whilst the chord remains the same throughout the whole length of the planes, the rear spars slope less back than do the front ones, so that the amount of overhang of the trailing edge is considerably more at the tips than at the root of the wings. This, of course, has the advantage of allowing larger ailerons to be fitted, as these are hinged to the rear spars. The main spars, the front one of which serves at the same time as leading edge, are made of spruce of rectangular section, over which are built the ribs, which have flanges of spruce and webs of whitewood. As has already been said, the angle of incidence diminishes towards the tip, but another point in which the Dunne differs from other machines is that the camber increases towards the tips, the centre ribs being nearly flat, while those at the tip have a very pronounced camber. The joint of the upper main planes occurs at the centre, while the lower planes butt against the sides of the nacelle.
   At the extremities of the wings, and in the gap between the main planes are two side curtains, which are fixed: that is to say, they are not in any way controllable from the pilot's seat. Hinged to the rear spars are four ailerons, which at the same time perform the functions of rudders and elevator. For climbing the ailerons on both sides are turned up, and the downward pressure thus caused, acting as it does on the part of the wings which lies to the rear of the centre of gravity, forces the nose of the machine upwards, or, more correctly speaking, forces the wing tips downwards, thus causing the machine to climb. For descent the reverse procedure is followed, i.e., the ailerons on both sides are depressed. It should be clearly understood that the right and left hand ailerons are worked independently, each pair being connected up to a separate lever in front of the pilot's seat. For making a turn, one lever is pulled backwards, while the other is pushed forward. Thus, for making a left-hand turn the right-hand lever is pushed forward, while the left-hand one is pulled backwards. The movement is in reality the same as that of turning the steering wheel of a motor car. In the forward part of the nacelle is the pilot's seat, from where he has an excellent view in all directions. In front of him is a dashboard with the instruments, whilst the top of the forward part of the nacelle is swept upwards to form a deflector, which sweeps the air up over the pilot's head. The passenger's seat is in the rear of the nacelle, and situated on top of the main petrol tank. As it is well to the rear of the V formed by the trailing edges of the main planes, the passenger has also an unrestricted view in all directions. In front of the passenger are two control levers, which are interconnected with those in front of the pilot, thus affording dual control, but, while the pilot's control levers can be locked in any position required on the quadrant on which they work, the passenger's levers are always left free so that only the pilot has it in his power to lock the controls. At the rear end of the nacelle is the 80 h.p. Gnome engine mounted on overhung bearings, and driving directly a propeller of 8 ft. 2 ins. diameter. On the upper longerons of the nacelle are mounted the oil tank and a small petrol service tank. Petrol flows from the main tank inside the nacelle to a small pump mounted on the rear skid struts, and driven by a miniature propeller. The pump forces the petrol up in the small service tank, whence it runs by gravity to the engine.
   The chassis is highly original, although somewhat complicated and, we should be inclined to think, offering a considerable amount of head resistance, but Mr. Dunne finds that its excellent qualities for landing on the roughest ground more than justifies its being retained. As it is fully illustrated in the accompanying sketches, a short description will suffice. The front portion consists of three pairs of struts carrying at their lower extremities two skids, from which is sprung by means of a transverse tube and rubber shock-absorbers another universally pivoted skid which takes the weight of the front part of the machine and prevents it from standing on its nose. To the rear of this portion of the chassis are the wheels, which are also flexibly mounted so that they can "give" in any direction. Springing is effected by means of very powerful coil springs and telescopic tubes. Four steel tubes forming an inverted pyramid carry at their lower extremities another skid which serves to keep the propeller from contact with the ground, whilst the wing tips are similarly protected by two skids mounted on the outer extremity of the lower main plane.
   The main petrol tank has a capacity of 22 gallons, and the small service tank holds 4 gallons, while 12 gallons of oil are carried in the oil tank on top of the nacelle. The weight of the machine empty is about 1,400 lbs., and her speed is in the neighbourhood of 55 m.p.h.


Flight, December 13, 1913.

THE STANDS AT THE PARIS AERO SHOW.

NIEUPORT DUNNE

The Nieuport firm are represented by four monoplanes and a biplane, the latter being a French-built Dunne biplane, which machines, it will be remembered, are now constructed in France by the Nieuport firm. In its general arrangement this machine is similar to the British-built Dunne biplanes, but one alteration which, we think, must be considered an improvement was noticeable. We refer to the chassis, which is of an entirely new and very simplified form; in fact, one is inclined to think that the other extreme has almost been reached, for whilst the British-built machines were fitted with a very complicated chassis, this structure has in the French machine been simplified to a degree that makes one question its efficiency. Not the least interesting of the monoplanes shown is the actual machine flown by Helen in his famous flights for the Coupe Michelin, in which he covered officially 16,046 kiloms. 600 metres, while the actual distance covered on these flights in thirty-nine consecutive days is claimed by the firm to be over 21,000 kiloms. The machine, although naturally slightly dirty, does not appear to be any the worse for wear, and is the best proof one could have of the excellence of the Nieuport workmanship.
Of the other monoplanes shown one is of the military type and is fitted with a machine gun, whilst the remaining two are a single-seater racing machine and a tandem two-seater.


Flight, January 3, 1914.

THE PARIS AERO SALON - 1913.

NIEUPORT.

<...>
   The Nieuport-built Dunne biplane completes this exhibit, but as the Dunne machine has been fully described quite recently in the columns of FLIGHT, there is no need to describe it here in detail. Several minor alterations have been made in the construction, for instance, the nacelle is built up of steel tubes, and is of a slightly different form from that of the British-built machine. Also the chassis has been altered, and is in this machine surprisingly like the chassis fitted on the Bleriot biplane. Another alteration is that all the inter-plane struts are made of streamlined steel tubes, whereas in the British machine, it will be remembered, they were made of spruce. The workmanship of this machine, as well as that of all the monoplanes, is of very high quality, as one might expect from a firm of Nieuport's standing.