In may 1901 he was awarded the Ph.D. degree in Law by the Law School and after graduation he returned to Lugoj. Here he accomplished his studies about human flight and designed his first flying machine which he called "the airplane-car". He tried to build this machine in Lugoj, but, because he had no material help, decided to go to Paris. On the first of July 1902 he arrived in Paris. Vuia was hoping that in Paris - considered at that time the center of the aviation world - he would find somebody interested in his project. In Paris, Vuia began to look for help among those interested in aerial navigation using balloons. But these persons did not believe that a flying machine which had a density greater than that of the air could fly, since their flight principles were based on Archimede's law. In these circumstances Vuia addressed Prof. Tatin, known as a very good theoretician. Tatin was interested in Vuia's project, but also tried to persuade him that he would do nothing, because his flying machine did not have a suitable engine (which was expected by all constructors of flying machines at that time). Tatin's main argument against Vuia's engine project, was that it had only one propeller, while all aircraft models which had flown had had two parallel counter-rotating propellers. However Vuia continued to sustain his project and submitted the "Self propelled airplane project" to the Science Academy of Paris on February 16, 1903. In this project he demonstrated the possibility of mechanical flight with a machine heavier than air. He also presented his procedure for take off. The special Commission for Aeronautics of the Paris Science Academy, considered Vuia's project an utopia. They rejected it, adding the comments: "The problem of flight with a machine heavier than air cannot be solved and it is a only a dream"...
Vuia did not give up and got a license for his machine from the Office of Industrial Property in France. On August 17, 1903 he received his license. It was officially published on October 16, 1903. Decided to give life to his project, Vuia had begun to build the flying machine during the winter of 1902-1903. Despite a lot of difficulties, the most important being the project funding, he succeeded in his attempt. During the fall of 1904, he began to build the appropriate engine, also his invention and in the same year, Vuia got a license for his aircraft in Great Britain.
This flying machine was called by his constructor "Vuia-1". It was a monoplane aircraft with a high-wing. The second difficult problem solved by Vuia was to build an engine which could develop a propulsion force to sustain the autonomous take off. The first airplane engine appeared in 1903, built by Wright brothers. The second one, built by Charles Manly was used by Prof. Langley for his airplane; he tried to fly with it two times in 1903 but he failed. The third engine was his own cration and was the second engine in the world to work on a flying machine - Vuia's engine can be seen in Paris, at "Air Museum" and a copy of it is in Bucharest, at "Romanian Air Force Museum".
While he was building his airplane Vuia received some visitors like George Besancon, Santos Dumont etc., well known personalities of aviation. Most of them were shocked by the fact that Vuia adopted a monoplane solution for his airplane, because all gliders which had flown by then were built after Lilienthal-Chanute twin wing idea. Vuia's argument was that he was inspired by nature - he used to say "I've never seen a bird with more than two wings". They were also worried because Vuia's machine had only one propeller so the airplane's stability was "difficult to maintain".
airplane was completely built in December 1905. Now Vuia had to chose
a suitable place to test his machine; he found a plain called Montesson,
near Paris, where he could not be disturbed by spectators. His first experiences
began in December 1905. In this period he used his machine only as a car;
the wings were not mounted on it. After he got used with his "car",
Vuia changed it into what he called "airplane-car", adding the
wings. In this configuration the machine was still used as a car only,
till it could attain safely a speed of 40 km/h without using the engine
at its maximum capacity. By now nobody, except one of the men who had
helped him building the machine, attended these experiences. In February,
after they heard of Vuia's successes, more people - including George Besancon
and others - joined him to see the attempts. During February many papers
in France began to devote large spaces to Vuia's machine. Considering
the weather warm enough, Vuia decided to make his first flying attempt
on March 18, 1906 . He had established to make the attempt in the afternoon,
so at three o'clock p.m. he turned on the engine. After five minutes his
machine began to move. After a short accelerated run of about 50 meters
"Vuia-1" left the soil and flew at a height of about
1 m. After about 12 m in flight, some problems occurred at the engine
so the propeller stopped and the aircraft landed.
In 1907 Vuia performed many flights. A notable event took place on March 27 when Vuia, Santos Dumont and Bleriot attended an aviation meeting at Bagatelle. Only Vuia succeeded in his attempt, while Santos Dumont and Bleriot could not even take off. Santos Dumont made only three flights during this period: the first on September 13, 1906, then October 23, November 12, 1906 when the first flight was officially controlled. After these Santos Dumont gave-up his first airplane and built a new one, completely different. In 1907 the number of autonomous flying machines increased rapidly; Charles Voisin on March 16 and 30, Louis Bleriot on July 11, 25 etc., Henri Farman on September 30, Esnault-Pelterie in October etc. After "Vuia-1", Traian Vuia built "Vuia-1 bis" which was equipped with the same engine but was enhanced by his constructor, and "Vuia-2" which was equipped with a new engine built by the French engineer Leon Levasseur. Vuia also built two helicopters in 1918 and 1922.