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Mattos, B.S. on the whirling arm for Henson and Stringfellow. This led to an airplane with a span wing of 6 m and an area of 5.84 m², powered by a small steam engine designed primarily by Henson but improved by Stringfellow. Some unsuccessful flight attempts were made with this type. The machine was not able to get airborne after being launched by a catapult system. Lack of suitable power and techniques for the construction of lightweight structures were the reasons for the Aerial Steam Carriage failure.

Due to the failure of his proposed enterprise, in 1848, William Henson and his wife, Sarah, left England and moved to the United States, settling in Newark, New Jersey, where he spent the last 40 years of his life. Henson had apparently ceased his aerial research for good, and never again took up the matter. Stringfellow stayed on and in 1848 tried once more to fly a model with an improved steam engine. The results were disappointing, nothing more than a short, uncontrolled hop. At this point, Stringfellow also gave up, and the entire episode was forgotten. However, the Ariel had some positive effects: its design prompted Cayley to rethink wing configuration and come up with the multiple-wing design, a feature of nearly all the early successful aircraft. The plane itself was logically designed and inspired many builders. Ariel configuration certainly influenced the Demoiselle from Santos-Dumont. Both planes presented a monoplane configuration featuring cambered airfoils. The materials were to be spars of bamboo and hollow wood, with diagonal wire bracing.

Other many flight attempts happened with aircraft powered by steam- and electric-engines. These flights were unsuccessful since such engines presented high-weight-to-power ratio at that time. Only after the internal combustion engine was improved, flying with a heavier-than-air aircraftbecame possible.

Putting an airplane airborne

In France, an Aviation community was established in the tum of 19th to 20th century. Most of people were friends, including Louis Blériot, Henri Farman, Gabriel and Charles Voisin, and Santos-Dumont. The latter was not a theoretician or a scientist, but he superbly integrated the technologies at his disposal at that time, in other words a technology integrator. In addition, he improved existing technology in many aspects, for example, lubrication of opposed-cylinders engines. He also invented devices and mechanisms to improve airship stability and maneuverability.

Santos-Dumont had been thinking about a heavier-than-air aircraft for a long time (Santos-Dumont, 1904). He initially considered a huge airplane based on Cayley’s ideas (Lins de Barros, 2003). A counter-rotating dual rotor helicopter was also constructed, but soon he was aware of the difficulties posed by a vertical takeoff concerning the required higher power-to-weight ratio, therefore he abandoned the concept. He tried some different concepts that simply did not work.

Years before the work to the construction of the monoplane began, Dumont was convinced by the Voisin brothers to switch to a biplane configuration, which should be shaped like a square kite called Hargrave box. On November 12, 1894, Lawrence Hargrave, the Australian inventor of the box kite, linked four of his kites together, added a sling seat, and flew 4.88 m. By demonstrating to a skeptical public that it was possible to build a safe and stable flying machine, Hargrave opened the door to other inventors and pioneers. The Hargrave-designed box kite, with its improved lift-to-drag ratio, was to provide the theoretical wing model that allowed the development of the first generation of European and American airplanes.

In 1905, the Voisin brothers ran a glider manufacturing business in partnership with Louis Blériot, in Paris. The box-kite configuration had been successfully employed in their glider designs (Fig. 7). During some trials on the Seine River, Santos-Dumont perceived that the Antoinette boat engine, which was employed to bring the glider airborne, could be fitted in a heavier-than-air machine (Fig. 7). On this way, the 14-bis was conceived. Again, we testify that there was an exchange of information, ideas, and even designs among the members of the aviation community in France.

Santos-Dumont properly did not follow entirely the Hargrave-box kite concept. He transformed a pair of wings incorporating a control surfaces box in a canard configuration. The 14-bis aircraft was constructed at Neuilly-Saint James on the outskirts of Paris and was exhaustively tested (Fig. 8). At first, the airship number 14 served as a support platform for evaluating the stability of the airplane and, for this reason, it was called 14BIS (Encore). Thus, Dumont also invented the flight test. Finally, he performed a few flights with his biplane and in France certified by Aéro-Club de France commission, who attended for the occasion.

Some months earlier, on August 21, 1906, Santos-Dumont made his first attempt to fly. He did not succeed because the 14BIS airplane was underpowered at this time. His next move, it was the re-engine of his aircraft with a 50-hp (37.3 KW) power plant, which he obtained through Louis Bréguet. He was ready for a new flight attempt. On September 13, Santos-Dumont 366 J. Aerosp. Technol. Manag., São José dos Campos, Vol.4, No 3, pp. 355-379, Jul.-Sep., 2012