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by bitmapbrother 3387 days ago
The circular runway is banked so I would assume crosswinds aren't as devastating due to this banking. However, I am curious as to why you so adamantly believe that circular banked runways guarantee crosswinds. Is this based on scientific research that have proven this or is this just a guess?
2 comments

> I would assume crosswinds aren't as devastating due to this banking.

You would assume incorrectly. The bank is mostly irrelevant. Crosswinds happen when the direction of motion of the plane is anything other than directly in to the wind. If you're turning, your heading is continually changing, and so the relative wind direction will be continually changing, and so you will necessarily have a crosswind component everywhere except at the one point when you are heading directly into the wind. Even worse, the crosswind component will be continually changing as you turn. This is even worse than it seems. Landing in a crosswind involves a maneuver called "cross-control" where you roll the plane into the wind with the ailerons while simultaneously apply opposite rudder to arrest the resulting turn. It's one of the hardest things to do in an airplane. Getting it right is tricky even when the runway is straight and level and the wind is steady. Trying to do it on a curved banked runway, where the wind is necessary continually shifting as you turn, would be a total nightmare.

> However, I am curious as to why you so adamantly believe that circular banked runways guarantee crosswinds. Is this based on scientific research that have proven this or is this just a guess?

I'm a pilot with over twenty years of experience. But you don't have to be a pilot to see the folly of circular runways. It's simple common sense: if you're turning, you can't be heading directly into the wind the whole time.

most obvious reason: gusts. wind is rarely stable in intensity and direction.

a secondary point: checkout any landing strip https://i.imgur.com/n99YiM5.png

a plane can't pinpoint the landing to absolute precision, even on autopilot. the dark patch should give you an idea on how much ahead/behind a large plane may land under real world condition - all the test they give in the papers are using small planes or even fighters, those can manage precise landing, a 737 not so much

the plane will have to follow the turn until it touches down, and as it follows the turn it'll change it's direction relative to crosswind, with all the implication it entails. few degrees on landing are already enough to need a significant correction.