I figured you were talking about that one particular sentence. You're cherry-picking this article. Hung up on a word that was used twice in the article.
This is when I began to ask myself should I even seriously engage this discussion further, because you're clearly bullshittin me.
No such section exists. Further proving you the type of individual you are.
You don't understand the article, which I can respect more from a person that can admit they don't understand something.
It's ok if you don't.
This article is my language.
A flat and non-rotating earth is a
model meant to be used to simplify the derivations of a set of equations without having to take into account the Coriolis effects from Earth's rotation, the turbulence generated elevated surfaces, and other parameters that can affect the flow of air. This is a simplified aerodynamic model.
This article has zero to do with any truth of the Earth being flat. It doesn't suggest it. Not even close.
Plus these equations take into account gravity which is completely against flat-earthers beliefs.