Prof. dr. eng. Andea Petru, Scientific Secretary of the Romanian Academy of Scientists
I will try to characterize the short but prodigious technical-scientific activity of Traian Vuia, whom we can truly consider a symbol of the inventive spirit of the people of Banat.
1. Vuia’s basic idea, which led him to conceive and name his flying machine “aeroplane – automobile”, was to combine two previous great technical achievements into a coherent whole:
- the automobile, which originally appeared as a tricycle (see Serpollet’s steam-engined carriage – in France, or Daimler’s petrol-engined tricycle – in Germany) and rapidly evolved into a quadricycle, becoming by the early 20th century an industrial product with an appreciable functional level and:-
- the glider with a wing on the wing, as developed by its predecessors, demonstrated and confirmed as a non-powered flying machine by the hundreds of gliding flights carried out in the last decade of the 19th century by Lilienthal and his emulators.
The car – in fact its rolling system on wheels – will allow the optimal solution of take-off and landing by providing by propeller thrust the speed necessary to obtain the lift force and the lift wing – obtaining the lift force for take-off from the ground and flight itself, after reaching by propeller thrust the necessary translation speed. It should be noted that, with this in mind, Vuia designed and built his flying machine from the outset as a powered aircraft, without going through the glider phase. Its particular merit, however, is that it has definitively established the take-off of the aircraft on wheels, demonstrating the superiority of this method over all others that had been tried.
- Contrary to the opinion and option of most of his direct competitors, Vuia designed and built his aircraft as a monoplane, with a single propeller, thus demonstrating that it is not mandatory to build the airframe with two or even more wings and that, on the other hand, the engine torque of the turnaround is not a problem that has a decisive impact on the flight and therefore on the construction of the aircraft.
Here again, Vuia’s particular merit is that he insisted on the affirmation and confirmation of the monoplane, in an era predominantly favourable to biplanes developed on the basis of cellular kites (designed and successfully experimented by the Australian Haargrave), such as the Chanute gliders, the Wright brothers’ “Flyer” series of airplanes, the Voisin, Bleriot, Santos-Dumont biplanes, etc.
Vuia’s intuition and technical talent will also guide him in the choice of detailed construction solutions and the materials used. Taking advantage of the technological expertise of the French bicycle industry, Vuia uses thin-walled steel tube construction for the strength structure of his machine, predating Anthony Fokker by almost 10 years, to whom this priority is attributed.
The carbon dioxide engine, designed and built by Vuia to power the aeroplane with which he made his epic flight on 18 March 1906 on the Montesson field, did not satisfy him because it was not powerful enough, was not very safe in operation, had poor efficiency and the working fluid used was consumable.
That’s why Vuia thought that the most suitable thermodynamic agent was high-pressure, high-temperature steam, which would expand in a turbine and drive the propeller. The tired steam was to be condensed and the condensate fed back into the steam generator.
Vuia saw the need to introduce three fundamental ideas into the design of this steam generator, which simply revolutionised the construction of steam generators: accelerated combustion, intensified heat transmission and a forced-flow boiler.
- Starting from the technically correct conception that the solution to the problem of the helicopter comes from the simultaneous achievement of lift and propulsion by the rotor, Vuia began documenting the propeller as early as 1907-1908. In order to obtain data on their efficiency (which he considered to be higher than the aerodynamicists of the time expected), Vuia designed and set up an experimental laboratory where, between 1914 and 1916 (with a break at the beginning of the First World War), he carried out – – for several types of propellers – 45 sets of experiments, each of which included tests at 21 values of rotational speeds…
The aims, method and results of the experiments were presented by Vuia in the technical report entitled “Etude experimental sur Ies plâns inclines en rotation” published in the 15 July 1919 issue of the Parisian magazine “L’Atmosphere” and republished in 1923 by the magazine “La Technique Aeronautique”.
In order to verify these conclusions, which for the most part proved to be correct, Vuia decided to design and build a helicopter himself. Vuia built in 1918 the study helicopter “Vuia No. 1”. This machine was equipped with two groups of rotating wings, each group consisting of two propellers with two blades each, rotating in opposite directions.
The helicopter’s horizontal displacement was to be achieved by tilting the axes of the rotating wings, whose maximum rotational speed obtained in the tests did not exceed 40 rpm; for these speeds, lift forces of the order of 57 – 59 kgf were obtained. Vuia originally planned that the rotors of this helicopter would be driven by pedals operated by the pilot-cyclist; it was tested in 1920 at the “Port Aviation” aerodrome at Juvisy, when the cyclist Gaston Degy succeeded in lifting the 120 kg of the assembly off the ground…
Structurally and dimensionally similar to its first helicopter, the “Vuia nr.2” was equipped with an FN engine of 8 hp and 53 kg, so that at 2650 rpm, the rotors rotated at 86 rpm, enough to lift the weight of the helicopter equipped with a pilot on board. The test flights were resumed in the autumn of 1925, on 31 October 1925, in the presence of journalists and friends, the helicopter “Vuia No. 2” flew a distance of 80 m at a height of 8 m and a take-off weight of 190 kg. The flights continued in 1925 and 1926, proving that the aircraft was stable, safe and maneuverable but, above all, demonstrating once again the genius and perseverance of the scientist, inventor and patriot who was TRAIAN VUIA…
Traian Vuia was a powerful creative force, an advanced spirit of his time, a pioneer of new paths in aviation and thermo-engineering, at the same time he was also a great patriot, who, in difficult times, put himself at the service of his homeland.
That is why, by dedicating to him now, 116 years after his first flight, this modest evocation, we are fulfilling a pious duty towards the man who set out from the Surducul bănățean to conquer the sky and succeeded!