And they only used a wooden rail the first year at Kitty Hawk, when they only had a glider. They had decided to tackle the problem of control first and propulsi

And they only used a wooden rail the first year at Kitty Hawk, when they only had a glider. They had decided to tackle the problem of control first and propulsion later. The glider took off by sliding downhill on a rail, while the Flyer they built the next year took off under its own power on level ground. Not only that, but they were the first to realize that the tables of lift published by whatshisname the French guy were bogus. They built a wind tunnel so that they could make their own measurements of lift and drag. Weirdly, the wind tunnel had been invented ~50 years earlier! Apparently most of the Europeans who were playing with gliders that whole time didn’t even know about wind tunnels or they might have thought to put two and two together.