Visitors to Washington D.C. this fall may want to explore a Smithsonian exhibition Codex on the Flight of Birds, which examines Leonardo da Vinci's studies and sketches dealing with flying machines, the nature of air, and bird flight. The exhibit will be at the National Air and Space Museum until October 22, 2013. (video)
From the Smithsonian website:
Hundreds of years before any real progress toward a practical flying machine was achieved, Leonardo expressed the seeds of the ideas that would lead to humans spreading their wings. This extraordinary document, exhibited outside of Italy only a few times, will be displayed in The Wright Brothers & The Invention of the Aerial Age gallery. The Codex exhibit will be a once-in-a-lifetime opportunity to appreciate the genius of da Vinci in the same space as the Wright Flyer, which made the airplane a reality four centuries after the Leonardo produced the Codex on the Flight of Birds.