<P> Designs similar to the Chinese helicopter toy appeared in Renaissance paintings and other works . </P> <P> It was not until the early 1480s, when Leonardo da Vinci created a design for a machine that could be described as an "aerial screw", that any recorded advancement was made towards vertical flight . His notes suggested that he built small flying models, but there were no indications for any provision to stop the rotor from making the craft rotate . As scientific knowledge increased and became more accepted, men continued to pursue the idea of vertical flight . Many of these later models and machines would more closely resemble the ancient bamboo flying top with spinning wings, rather than Leonardo's screw . </P> <P> In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a wound - up spring device and demonstrated it to the Russian Academy of Sciences . It was powered by a spring, and was suggested as a method to lift meteorological instruments . In 1783, Christian de Launoy, and his mechanic, Bienvenu, used a coaxial version of the Chinese top in a model consisting of contrarotating turkey flight feathers as rotor blades, and in 1784, demonstrated it to the French Academy of Sciences . A dirigible airship was described by Jean Baptiste Marie Meusnier presented in 1783 . The drawings depict a 260 - foot - long (79 m) streamlined envelope with internal ballonnets that could be used for regulating lift . The airship was designed to be driven by three propellers . In 1784 Jean - Pierre Blanchard fitted a hand - powered propeller to a balloon, the first recorded means of propulsion carried aloft . Sir George Cayley, influenced by a childhood fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu, but powered by rubber bands . By the end of the century, he had progressed to using sheets of tin for rotor blades and springs for power . His writings on his experiments and models would become influential on future aviation pioneers . </P> <P> William Bland sent designs for his "Atmotic Airship" to the Great Exhibition held in London in 1851, where a model was displayed . This was an elongated balloon with a steam engine driving twin propellers suspended underneath . Alphonse Pénaud developed coaxial rotor model helicopter toys in 1870, also powered by rubber bands . In 1872 Dupuy de Lome launched a large navigable balloon, which was driven by a large propeller turned by eight men . Hiram Maxim built a craft that weighed 3.5 tons, with a 110 - foot (34 - meter) wingspan that was powered by two 360 - horsepower (270 - kW) steam engines driving two propellers . In 1894, his machine was tested with overhead rails to prevent it from rising . The test showed that it had enough lift to take off . One of Pénaud's toys, given as a gift by their father, inspired the Wright brothers to pursue the dream of flight . The twisted airfoil (aerofoil) shape of an aircraft propeller was pioneered by the Wright Brothers . While some earlier engineers had attempted to model air propellers on marine propellers, the Wright Brothers realized that a propeller is essentially the same as a wing, and were able to use data from their earlier wind tunnel experiments on wings, introducing a twist along the length of the blades . This was necessary to maintain a more uniform angle of attack of the blade along its length . Their original propeller blades had an efficiency of about 82%, compared to the 90% of modern propellers . </P>

What are the different numbers of propeller blades an airplane can have