In Assassin's Creed II, which Leonardo da Vinci invention lets Ezio fly over Renaissance Venice?

In Assassin's Creed II, Leonardo da Vinci's flying machine lets Ezio fly over Renaissance Venice.

Leonardo modifies a design based on the study of birds and uses it to help Ezio reach the Doge's Palace during the Venetian portion of the story. The sequence is a memorable example of the game blending historical personalities with imaginative adventure. It also demonstrates Leonardo's role as Ezio's inventor and ally, since he translates designs from his codex into practical tools and weapons.

The machine is inspired by Leonardo's real investigations into human flight, including sketches of ornithopters and other winged devices. There is no evidence that Leonardo built a working aircraft capable of carrying a person in Renaissance Italy, so the playable flight is fictionalized. The vehicle is also distinct from the parachute Leonardo later provides. Ezio's flight over Venice is a short mission sequence rather than a freely available aircraft system, and it is tied specifically to the game's fictional conspiracy surrounding the city's ruling powers.