Since ancient times, the illusion of human flight has haunted thousands of inventors, as evidenced by the mythological story of Icarus and the flying machines sketched by Leonardo da Vinci. However, in 1680, after spending many hours studying the flight of birds, the Italian physiologist and physicist concluded that humans could never fly using their own means. Therefore, after the impressive inventions of the Montgolfier brothers, many believed the solution to human flight lay in lighter-than-air devices.
Yet, when considering replacing muscle power with a machine, the idea of heavier-than-air flight gained support. Leading the charge was the forward-thinking Englishman, George Cayley. In his book “On Aerial Navigation,” published in 1809, he articulated the principle of the airplane (“using a lifting surface to raise a heavy object by overcoming air resistance, thanks to a machine”) and described the main components, including the propeller. He created a small model in 1804 and several gliders from 1809; however, he lacked a sufficiently lightweight engine. Cayley’s research was continued by William S. Henson. Henson’s collaborator, engineer John Stringfellow, built a scale model of a “steam-powered flying carriage,” which successfully glided several times in 1848, as the engine’s weight prevented it from ascending but allowed it to extend its glide path.
The works of Cayley must also be compared to the equally commendable efforts of Alphonse Pénaud. After being accepted to the Maritime Academy, he contracted polio and focused solely on aeronautics, creating flying models that led him to develop stable propulsion systems, particularly with wings and tail surfaces shaped like a wide-open V. In his works, he anticipated the arrow-shaped wing, retractable landing gear, and control surfaces. In 1817, his Planophore, measuring 50 cm, with wings powered by twisted rubber bands, astonished visitors at the Tuileries Garden. He drafted designs for a machine capable of flight with a pilot and received a patent in 1876, but lacked the financial means to realize it; suffering from illness and depression, he took his own life. Toy manufacturers showcased the Planophore worldwide. In 1878, one of these toys was gifted to the Wright brothers in the U.S., igniting their passion for aviation.
Louis Mouillard, another aviation enthusiast engineer, initially drew inspiration from birds but later recognized the advantages of rigid wing designs, as evidenced by his two books: “The Kingdom of the Air: A Study of Birds Applied to Aviation” and “Flying Without Flapping.” Disabled, he had to abandon his glider experiments. Cayley and Pénaud established a general formula for future aircraft.
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Nonetheless, it is important to acknowledge Clément Ader, who did not wait for the necessary advancements in cells and engines and constructed machines powered by steam-driven propellers. In 1890, he succeeded with Éole, his first aircraft. Following this was Avion, which later came to represent the term aeroplane; with this, in 1897, under poor weather conditions, he flew 300 meters at an altitude of 1 meter before an official committee, which remained unconvinced and departed. Lacking support from authorities, Ader subsequently withdrew from his research. Concurrently, American-born Englishman Hiram Stevens Maxim built a massive biplane powered by twin propellers, each nearly 5.5 meters in diameter and driven by a 180 horsepower steam engine. Despite its incompleteness, it managed to lift off the ground in 1894. After demonstrating that sufficiently powerful engines could lift a heavy machine (up to 3,500 kg), Maxim concluded his experiments.
The first significant scientific contribution toward perfecting gliders came from German engineer Otto Lilienthal. After extensive study of bird flight and documenting his observations in “The Flight of Birds as the Foundation of Aviation,” he began a series of glider experiments in 1891. He conducted no fewer than 2,000 flights until 1896, when he tragically died from a fall of 15 meters. A French engineer who later became a U.S. citizen, Octave Chanute, well-versed in Lilienthal’s works and having received Mouillard’s findings and untested ideas, pursued the research of his predecessors since 1875. In 1896, following Lilienthal’s death, Chanute, at 64 years old, took up the mantle of leadership, improving upon the last biplane designed by Lilienthal and inventing a method to connect the wings using bracing wires and struts (a method that would be used indefinitely), and conducted several experiments. Ultimately, his gliders, with their warped wings and added control surfaces, became true cells ready to accept an engine. He conceptualized this in 1900 when he met Wilbur Wright and his talented, passionate brother Orville, eventually becoming their advisor and close friend.
Finally, among those recognized for heralding the birth of aviation was the distinguished American astronomer Samuel P. Langley, who was deeply interested in aeronautics from 1886 to 1906. As early as 1896, he created small motorized models that flew 1,200 meters. He later collaborated with American engineer Charles M. Manly, who built a 50-horsepower engine weighing 95 kg, which he installed on an aircraft called Aerodrome. In 1903, this machine, piloted by Manly, attempted to launch twice from a specially designed boat, but both times, due to faulty launching mechanisms, it crashed into the Potomac River. Faced with ridicule and mockery from the press, Langley permanently ceased his experiments.
By 1900, the cumulative experiments conducted by all these forerunners had sufficiently equipped an inventor, equipped with methods and persistence, to successfully lift a machine powered by mechanical propulsion carrying a person into the sky. This inventor, a bicycle manufacturer and member of the Wright family, had a brother equally talented, passionate, and persistent as he was, and moreover, the two brothers found in Chanute a mentor who was a dedicated engineer with 25 years of research and experimentation in aviation.
From 1900 to 1903, the Wright brothers undertook nearly 1,000 glider flights on a windy beach. Their experiments often faced interruptions, and during the breaks between flights, they returned to their workshop to test small models in a wind tunnel they built. As a result, from Chanute’s final glider, they refined a third glider design characterized by sturdy wings extended, reduced curvature, and added a control device allowing them to bank (previously, when the glider tilted to one side, the pilot had to shift their weight to the opposite side to maintain balance; with the banking method, the wing’s leading edge would rise on one side while lowering on the other, effectively reversing the tilt motion). After achieving a stable glider, the Wright brothers sought to solve the thrust problem, and lacking external support, they built a lightweight engine (83 kg for 13 horsepower) themselves. Ultimately, they successfully created a highly effective propeller for that time (the machine featured two counter-rotating propellers driven by a belt and bicycle chain).
The first test flights were conducted at the end of 1903. Although representing the pinnacle of technology at that time, this machine could not take off under its own power and had to be launched from a wooden ramp. The first takeoff attempt failed due to a steering error by Wilbur (who was chosen by a coin toss for the first trial). The second attempt allowed Orville to achieve a “flight” lasting 12 seconds, covering 36 meters. On the same day, he succeeded in remaining airborne for 59 seconds and traveling 260 meters. Thus, the airplane was born.
As soon as the news broke, dozens of inventors dedicated themselves to perfecting the airplane. In 1906, engineer Robert Esnault-Pelterie created a monoplane, in which he invented the control stick and a star-shaped engine. By 1908, lift had improved to the point where Henri Farman could make the first flight carrying an additional person. Very soon, the shaky frames of the first airplanes had to give way to the modern design of aircraft. Louis Blériot embraced this formula and defended it throughout his life. In 1910, German Hugo Junkers designed a biplane with a wing structure that ensured rigidity from one end to the other. In 1913