Читать книгу The Rise of the Flying Machine - Hugo Byttebier - Страница 18

Pénaud’s Master Patent

In spite of the optimal results of his flapping-wing model, Pénaud remained convinced that “Only the aeroplanes give hope for building full-size machines”. But Pénaud remained for the time being alone in his outlook. The Franco-Prussian War of 1870-1871, and the contact which the beleaguered city of Paris had with the outside world by means of balloons, had turned the attention of the aeronautically minded towards the emergence of the dirigible balloon, which was thought to be around the corner.

In 1875, Pénaud published a complete theory of soaring flight that, according to his perception, was only possible because rising currents of air counteracted the downward glide of the bird under the attraction of gravity. He had already remarked on this in an article published in 1871 dealing with the possibility of human flight without power. Soaring was, like the flight of the kite, flying by the power of the sun.

At a Société meeting on 3 December 1875 Pénaud declared: “We know the true theory of flight, the demonstration of it has been done. We have now only to replace the elastics by heat engines of sufficient power and capable of continuous action.”

Pénaud worked hard during the year to arrive at the specifications for a great man-carrying aeroplane. Several sketches of modern-looking aircraft have survived though the definitive choice, for which a patent was applied and granted, was a kind of flying wing, a step away from the planophore concept. He was probably anxious to cover as great a wing area as possible and fought shy of the construction problems related to wings of high aspect ratio.

Pénaud’s patent (No. 111,574) of 16 February 1876, applied for in his name and that of Paul Gauchot (a mechanically minded enthusiast with whom he had become friendly) is generally regarded as describing a typical aeroplane but when the patent is analysed carefully it is clear that what Pénaud had been striving for was a patent for “The Aeroplane” in generic terms.

What is amazing about this patent is the great amount of modern details. It contained two propellers in front, a retractable undercarriage, a cockpit with windshield for the pilot, a simple steering device for control, a vertical fin and rudder at the rear, variable-pitch propellers and much more.

A provision was included for movable wing tips that “by their resistance to the air would make the apparatus turn”. These were visualized as a kind of movable wingtip rudders, not in order to redress the aeroplane when starting an involuntary roll, as Boulton’s patent of 1868 had specified.

Taking off was to be effected by accelerating over the ground and landing was to be in the manner generally used today. He had also been careful to specify that the construction should be of wood or of metal and on the whole tried not to overlook any detail.

Full attention was given to the powerplant, making sure that no existing engine could be used without falling under the specifications of the patent. All the types of steam engine were mentioned and also “all the engines working with gas explosions known today; specially those working with a mixture of air and gas” nor was the use of engines working with a liquid fuel forgotten. One is left wondering how many aircraft builders today would fall under Pénaud’s patent if it were still valid. But the legal year for expiry was 1891 and at that date there were still no aeroplanes flying anywhere.