L.Opdyke French Aeroplanes Before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
Avion III: It featured 2 slightly smaller steam engines driving 2 slightly smaller counter-rotating propellers, one of which was mounted slightly ahead of the other. The airframe was built, laboriously and beautifully, of small lengths of wood and bamboo joined together with glue and wrapped with fabric; the result was very light. The propellers were made of light strips of bamboo assembled exactly like bird feathers. The wings were intricately articulated: a main spar hinged, with smaller spars towards the ends branching off; the sections of spar and the joints themselves were referred to as elbow, hand, thumb, and fingers. Fabric was applied to the wing with thousands of tiny buttons, none taking much stress. The multiple wing adjustments of Eole had been reduced to one: both wings could be swung forwards and backwards to move the center of pressure, controlled by a single wheel requiring 20-30 turns for full travel. A small fabric rudder was attached to the steerable rear wheel for control of yaw, and the 2 propellers could be adjusted to turn at different speeds for further effect.
On 12 October 1897 he made the first test on a circular track of his own design at Satory: it was a driving test only, and showed the machine could travel under its own power. It did not leave the ground, nor was that the purpose of this test.
The second trial occurred on 15 October, and Avion III circled the track until the wind came from behind; the machine tipped forward enough to lift the rear steering wheel off the ground, and careened off the track into the field, slewed around in a sort of groundloop, and came to a halt, badly damaged. General Mensier's report on this trial, describing it exactly in this way, was not released to the public until November 1910, long after Ader had been exhibiting Avion III and had made claims for this final trial as a real flight, completely at variance with the official military report.
Avion III was recently under study at Chalais-Meudon, one of the original wings being restored, complete with curved hollow wooden spars, hinges, and cover, with the aim of proving the design's aerodynamic qualities.
(Span: 15.3 m; length: 5.45 m; wing area: 37.95 sqm; empty weight: 246 kg; gross weight with pilot: 455 kg)
Avion IV: While Ader was repairing Avion III, he began work on Avion IV, similar to III but with the twin propellers further apart, and with fully castering wheels. But in February 1898 the Army canceled Ader's contracts and gave up research into flying machines; Avion III was preserved for posterity, now at the Musee des Arts et Metiers and fully restored and recovered in pink fabric; and Avion IV was never finished.
A.Andrews. The Flying Machine: Its Evolution through the Ages (Putnam)
Commissioned by the French War Ministry, Ader went on to construct a series of further machines, which crystallised into a complicated movable-wing twin-engined steamer called Avion III. During two tests of this machine on a circular track in October 1897 Ader completed one circuit under power, but always earthbound, and then succumbed to a gust of wind, which blew him off the track and put him hors de combat. Nine years later he claimed, again falsely, that he had achieved a smooth flight of 300m in Avion III.
Журнал Flight
Flight, January 2, 1909
AEROPLANE DESIGN AND CONSTRUCTION.
Ader - A Pioneer.
In the electrical world, the name of M. Ader is one of renown for his valuable work in connection with telephones; in the new realm of flight he has an almost equal claim to respect, for he was an early pioneer who not only diligently laboured to attain the conquest of the air, but actually achieved some measure of success. It is on record that he flew a distance of 50 metres on October 9th, 1890, in the grounds of the Chateau d'Armain villiers, and subsequently, on October 14th, 1897, he flew a distance of 300 metres at Satory before a committee of army officers delegated by the French Government to witness the trial.
The machine was undoubtedly in the air - as shown by the absence of wheel tracks in the wet ground-while it travelled this latter distance, but its direction of flight was, owing to a strong cross-wind, far from the circular course marked out, and this fact, coupled with the damage done to the machine in landing, doubtless led the principal officials to take a gloomy view of its prospects. At any rate, the Government refused to continue its financial assistance to the inventor, and M. Ader had reluctantly to abandon his favourite work.
The histories of many pioneers are sad, especially if they are before their time - and Ader was certainly that. Being a Frenchman, he was born in a sympathetic land, however, but even so, he was very fortunate to get so far as to gain the assistance of the Government at such an early stage in the proceedings. M. Ader himself was an enthusiast on flight from boyhood, and was of course, therefore regarded by many as a mere dreamer. That was in the days before he became sufficiently wealthy as an electrical engineer to put some of his ideas into practice. To modern eyes, his attempts seemed doomed to failure, it is true, but he did his best with the materials at his disposal, and his name unquestionably deserves to go down to history among those of the great. And, although he himself is now perhaps past taking an active interest in modern work, his engineer, M. Espinosa, is actively engaged in the industry.
His Avions.
Ader built three flying machines, and it is the last of these that has been taken from the museum of the Arts et Metiers to grace the first Aeronautical Exhibition; the others no longer exist. His first machine he called " L'Eole," and with that he achieved the flight of 50 metres in 1890; the third machine, on view in the Grand Palais, is the " Avion," with which he demonstrated before the French Government in 1897.
It is a machine of the monoplane type, constructed to resemble a bird in its general shape. Its wings are deeply cambered and arched, and their surface material is stretched over an elaborate framework, presumably intended as a copy of the natural formation of a bird's wing. The wings have a total spread of 16 metres, and present an area of 56 sq. metres ; they extend on either side of the body, and are so mounted that they can be swung forwards or backwards slightly in order to shift the centre of pressure relatively to the centre of gravity when desiring to ascend or descend. Beneath the rear portion of the wings, which extend far back in the centre, is a rudder controlled by pedals.
The mechanism, all of which is carried by the main body, consists of a multi-tubular alcohol-fired boiler and two horizontal compound engines. The boiler was rated at 40-h.p., and, when working at 10 atmospheres (140 lbs. per sq. in.), the steam in the dome was usually about 215 degrees C. The engines are placed in front with their cylinders horizontal and their crankshafts longitudinal. Each is coupled direct to the shaft of a tractor screw. They are compound engines with two high-pressure and two low-pressure cylinders each, the dimensions being 65 and 100 mm. bore by 100 mm. stroke. At the normal boiler pressure they developed 20-h.p. each at a speed of 600 r.p.m.; their weight is 21 kilogs. each.
The propellers are most peculiar, for they resemble nothing so much as eight gigantic quill pens arranged in two sets of four. The blades are, in fact, imitation feathers, and are made of bamboo. Each propeller is three metres in diameter, and has a pitch approximating to three metres (it is impossible to give an exact figure with such a form of construction). Their position is such, too, that they overlap one another considerably, and it appears as if that on the port side must have been working under difficulties.
Quite the most interesting fact about the " Avion " is that its entire weight was only 258 kilogs. This is due to the use of nothing but wood in the construction of the framework, and a system of making the joints and employing hollow struts and beams was thought out by M. Ader for the purpose; it is the same as is now put into practice by the Soc. Cons. d'Appareils Aeriens, of which M. Espinosa (M. Ader's engineer) is a Director.
Flight, July 5, 1913.
THE PIONEERS.
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The earlier history of aviation in France include the names of Penaud, who may be said to be the inventor of the model aeroplane, for he was the first to employ an elastic motor in 1871. Tatin was one of the first to experiment with power-driven models in 1879, when he used compressed air. Ader, the famous electrical engineer, whose name is identified with telephones, built three steam-driven monoplanes of curious bat-like form, but his success was apparently of the same order as that of Maxim. His machines were constructed almost entirely of hollow spars, and were exceptionally light for their size.
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L.Opdyke - French Aeroplanes Before the Great War /Schiffer/
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The Avion III as exhibited at the Paris Exposition Internationale de Locomotion Aerienne of 1908.
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P.Jarrett - Pioneer Aircraft: Early Aviation Before 1914 /Putnam/
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The restored Avion III on display at the Musee des Arts et Metiers in Paris. Its powerplant has been removed and is displayed nearby. The twin counter-rotating propellers are mounted with the starboard unit slightly behind the port to enable their discs to overlap.
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Журнал - Flight за 1909 г.
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PARIS AERO SALON. - Front view of Ader's "Avion No. 3." The bird-like appearance of the machine is well shown, as also are the curious feather propellers.
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Журнал - Flight за 1909 г.
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PARIS AERO SALON. - General view of the principal part of the Aviation Section. In the foreground, a little to the left, is a back view of Ader's "Avion," to the right is the R.E.P. monoplane, and opposite to it is the Delagrange biplane. In mid-air is the "Ville de Bordeaux," and in the distance, down the Grande Nef, can be seen part of a spherical balloon.
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L.Opdyke - French Aeroplanes Before the Great War /Schiffer/
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The fuselage and cabin of Avion III as it was being restored at the Musee de l'Air in 1982.
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A.Andrews - The Flying Maschine: Its Evolution through the Ages /Putnam/
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Ader brought in two 20hp steam engines to drive his Avion III, again of simulated bat-wing construction, with variable sweep-back wings intended to shift the centre of pressure during flight. Ader falsely claimed that he flew for 300m in this machine in 1897. Avion III was constructed as the result of a commission from the French War Ministry, the first indication by any government of a practical interest, backed by central finance, in the development of the flying machine. This picture is faked.
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Журнал - Flight за 1917 г.
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Журнал - Flight за 1913 г.
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Ader's Avion, a steam-driven bat-like monoplane built by the famous electrical engineer, and tried in 1897. It is said to have lifted itself off the ground for a brief period during a test in the presence of the French Army authorities.
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