Leonardo da Vinci Creates his Aerial Screw Drawing
In the late 1400s, Leonardo da Vinci created his aerial screw drawing in his notebook. Because da Vinci was so observant of nature and his surroundings, it is believed this design was partly based on his observations of the spinning of maple seeds as they fall to the ground. It also closely resembled Archimedes' screw used for irrigation purposes in 200 BC. This screw was used to move water from a canal or other water source to an area of higher ground. In order to power the aerial screw, four men, standing on the platform, are required to push the four wooden shafts in a circular motion. Da Vinci believed this would generate enough force to lift the machine into the air. He intended for the aerial screw to be made of reed, linen, and wire. Although he never created a physical model of this design, we now know that da Vinci's aerial screw would be too heavy to be lifted into the air. The force generated by the four men is not strong enough to overcome the strong pull of gravity from this heavy device.
The aerial screw design is interesting because it contains no elements that resemble birds. Da Vinci realized wings enable birds to fly but wings are not required for flight. Ahead in his understanding of aerodynamics, da Vinci realized flight occurs due to the compression of air. He used this principle in his aerial screw design, which relies on the circular motion of the device compressing the air below and causing the top portion to lift.
Image Source:
https://commons.wikimedia.org/wiki/File:Leonardo_da_Vinci_helicopter.jpg
Text Sources:
Capra, F. (2014). Learning from Leonardo: Decoding the notebooks of a genius.San Franciso: BK, Berrett-Koehler.
Foley, W. (1976). From da Vinci to the present—a review of airscrew theory for helicopters, propellers, windmills and engines.Paper presented at AIAA 9thFluid and Plasma Dynamics Conference, San Diego, CA.
Giacomelli, R. (1930). The aerodynamics of Leonardo da Vinci. The Journal of the Royal Aeronautical Society, 34(240), 1016-1038.
The Helicopter. (n.d.). Retrieved from http://www.leonardodavincisinventions.com/inventions-for-flight/leonardo-da-vinci-helicopter/.
Leonardo da Vinci: The aerial screw. (2017). Retrieved from https://www.elenco.com/wp-content/uploads/2017/10/EDU61002-2.pdf.