Among the inventions of the famous man of multifaceted Florentine spirit is the aerial screw, a kind of spacecraft developed in the 15th century. Many believe that it is the ancestor of the helicopter.
The aerial screw is a vertical flight propeller-driven aircraft whose plan would have been drawn by one of Leonardo da Vinci’s notebooks between 1487 and 1490. This concept, which had never been tested at the time, was based on a principle already known since Antiquity: the Archimedes screw designed to bring water up. The aerial screw is the first device evoking vertical flight and this Leonardo da Vinci machine was based on two theories:
“If this screw can force water to move in the opposite direction to its natural direction, i.e. from bottom to top, it is likely that a suitable screw can move in the same way in this other fluid that is the air that surrounds us. »
“The force with which a thing goes against the air is equal to that of the air against the thing. »
Leonardo da Vinci, who at the time was a military engineer on behalf of the Duke of Milan, Ludovico Sforza, had imagined the aerial screw in the context of his scientific studies. Although some believe that this is an invention that gave rise to today’s helicopter, this vision is generally considered to be utopian.
Leonardo da Vinci was very interested in the air he studied to come to the conclusion that unlike water, it can be compressed under the effect of a sufficient force. He also believed that if air can be compressed, it can also have material density and that from this assertion, a screw-shaped craft rotating at high speed can easily rise in the air.
However, the speed of rotation to be reached was not really evaluated, but was surely too high for the means of the time. The energy required to actuate this rotation was questionable, as was the actual modus operandi of launching the screw, although the intervention of human operators or some kind of quickly released cable as in the case of a spinning top.
Although he did not really think about the question of the energy needed to launch the screw into the air, Leonardo da Vinci was sure of his project:
“If this instrument, which has the shape of a screw, is well made, that is to say made of linen cloth whose pores are clogged with starch, and if it is rotated rapidly, I estimate that this screw will make its nut in the air and it will rise. »
Sources: Free University of Brussels – Futura Sciences