Leonardo Da Vinci was very interested in the possibility of flight for humans, which explains his extensive study on birds and their ability to fly. This was highlighted through his Codex of Flight of Birds. Though there were extensive drawings on a human-powered flying contraption, called the Ornithopter,  Da Vinci soon came to the conclusion that humans themselves were not powerful enough to support the lift-off of the machine nor were they strong enough to support the machine through the flight. However, the device in itself was brilliant because it modeled the human to be positioned such that center of gravity would enable flight and the wings flapped using a pedal, rod, and pulley system. Lastly, we believe that the machine was also extensively tested for flight, through evidence from his associates however there is no evidence of the creation of the machine itself.

Sources:-

“Flying Machine.” Leonardo da Vinci's Flying Machine Invention, www.da-vinci-inventions.com/flying-machine.aspx.

FLYING MACHINES - Leonardo da Vinci, www.flyingmachines.org/davi.html.

Fuller, John. “Top 10 Bungled Attempts at One-Person Flight.” HowStuffWorks Science, HowStuffWorks, 8 Mar. 2018, science.howstuffworks.com/transport/flight/classic/ten-bungled-flight-attempt2.html.

 Image Courtesy:- Wikimedia Commons, public domain

https://commons.wikimedia.org/wiki/File:Design_for_a_Flying_Machine.jpg