L.Opdyke French Aeroplanes Before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
Then Koechlin went off on his own and designed the monoplane which he developed steadily until 1911.
The basic design had a rectangular wooden fuselage covered with ash-and-mahogany ply, avoiding the need for wire bracing and turnbuckles The trapezoidal wings were formed on 2 steel tube spars, with wooden ribs, and aluminum sheeting; they were said to be very rigid. The tailplane was triangular, with a warping trailing edge; the vertical surfaces consisted of a square rudder and triangular fin, with another fin below which developed into a second rudder. Both mainwheels and the tailwheel castered; 2 skids were later added in front. A steering wheel and tilting column controlled the rudder and elevator, and the ailerons were linked to the pilot's back, though the first version had neither wing-warping nor ailerons but probably under-surface spoilers; small ailerons appeared first on the trailing edges and then at the wingtips to pivot on the front spar.
The first Koechlin monoplane flew first at the end of 1909; at the subsequent Salon its varnished ply skin drew favorable attention. At least 2 monoplanes were flying by the end of 1909, one built for Koechlin, the other for de Nabat. Others may have been built in 1910; on one of the first a Mrs Niel became the first woman to receive her brevet on a monoplane. In 1910 Koechlin offered a monoplane to the Army; in 1911 the Army ordered one, fitted with a 70 hp Gnome: it may have been the same one. 3 variants were offered in 1910; they may not have been built.
Type A: a single-seater.
(Span: 8.5 m; chord: 2.5 m; wing area: c 17 sqm: empty weight: 260 kg; speed: c 70 kmh; 20-28 hp Gregoire-Gyp or Anzani)
Type B: similar but "stronger": more powerful, with a 40 hp Gregoire-Gyp.
Type C: a 2-seater.
(Span: 11 m; wing area: 25.2 sqm; 50 or 70 hp Gnome or similar engine)
Flight, November 27, 1909
FLYER SILHOUETTES FROM THE PARIS SALON.
Monoplane, in which the two principal points of interest arc the watertight wood body and the method of warping the wings.
The body is constructed like a light racing skiff, but is flat-bottomed throughout. It is also decked in except for a small cockpit accommodating the pilot's seat. In order that the lines of the body shall be disturbed as little as possible, the engine has been mounted outside on a bracket which projects in front of the "bows."
The wings are supported on tubular steel spars, as shown in an accompanying sketch, and near the extremities of the smaller tubes, which are adjacent to the trailing edge of the wings, two short wooden cross-pieces are hinged. These little levers are anchored to the chassis frame by wires passing from their lower extremities, and also to the back of the pilot's seat by wires attached to their upper ends. The back of the pilot's seat is pivoted so that it sways with his body, and consequently if he leans over to the left he is able to pull upon the upper wire passing to the top side of the lever on the right hand wing. At first sight it might be supposed that this would have no effect other than to put the tubular steel spar in compression, for the wire lies nearly horizontal above the wing. The spar itself, however, is initially slightly curved, and under additional stress bends still further into an arch concave to the earth. The wooden lever is merely a device for applying a force to the axis of the rod, and the lever is hinged so that the fulcrum afforded by its anchorage shall be maintained when the spar bends. The system is illustrated by an accompanying diagram, and another sketch relating to this machine shows the method of flexing the tail for use as an elevator. A rudder is provided at the rear.
Flight, December 31, 1910
AEROPLANE SILHOUETTES FROM THE PARIS SHOW.
THE KOECHLIN MONOPLANE.
A FRENCH-BUILT monoplane, constructed at Billancourt. Framework of poplar wood with ash spars. It is on a machine of this make that Madame Niel, the first lady to obtain a pilot's certificate on a monoplane, has made many good flights.
General Dimensions. - Span, 10 metres; carrying surface, 26 square metres; overall length, 9.5 metres.
Seating capacity. - Two, one behind the other.
Chassis. - Two wheels arranged with a single skid in the centre; the wheels are so arranged that they adapt themselves to any unevenness in the ground over which they are travelling, while the skid is designed to protect the propeller when landing.
Engine. - 70-h.p. 4-cyl. Labor, but a 50-h.p. Gnome or 50-h.p. Chenu motor can be fitted at slightly increased price.
Propeller. - Two-bladed Koechlin, made of wood, 2.5 metres diameter, 1.8 metres pitch.
Tail. - This consists of a fiat plane, the rear end of which is flexible, to form an elevating flap. A vertical rudder is fitted above this tail plane, while in front is a triangular fin. A fin is also fitted below the tail.
Lateral stability. - Maintained by movable tips at the ends of the main plane.
Weight. - 320 kilogs.
Speed. - Not stated.
System of control. - By a single wheel of the motor car type mounted in front of the pilot. A backward or forward motion flexes the elevator, while the rotation of the wheel to the left or right operates the vertical rudders. For controlling lateral stability the wing tips are operated by the movement of the back of the pilot's seat, and it is claimed that this is done instinctively. The feet play no part in the steering.
Price. - Without motor, 13,000 francs; with Labor motor, 21,000 francs; and with 50-h.p. Gnome motor, 26,000 francs. The price of the single-seated machine is 11,000 francs without motor.