A few years ago I saw a TV program about a modern hang glider capable of carrying a human pilot based on a design taken from one of Leonardo DaVinci's notebooks. The modern designers tried to exactly duplicate Leonardo's design. A young lady successfully flew the glider a distance of about 300 feet.
No one really knows if the glider ever went beyond the notebook stage in Leonardo's lifetime, but the modern replica suggests it might have worked in his day if it had been built.
