[mannykannot]

Well, you can use models and wind tunnels, which, as Walter alludes to, the Wrights, unlike many of their competitors, did. The Wright Flyer was not airworthy by modern standards, but it served their purpose, which was to validate their approach and establish precedence.

The state of aerodynamics in 190x was more advanced than I suspect you imagine, with Lanchester on the right track in thinking about vorticity. Here's an interesting article on the divide between theorists and practitioners (which the Wrights partially, but not completely, bridged - and the theorists were evidently not all communicating with each other, either), and it also mentions the flawed assumption, of flying being like boating, that I mentioned in my earlier post.

https://www.aerosociety.com/media/4846/fw-lanchester-and-the...

It also shows that Lanchester, regardless of his theoretical chops, was not a successful airplane designer! He comes across as putting too much emphasis on how he thought things should be.