Hi,

I understand that planes [ideally] take off and land against the wind.

So for small airports w/ only 1 runway, do they build it to the direction that the wind is most likely to blow?

What about airports w/ 2 runways? Do they build them perpendicular to each other to maximize the chance of being able to take off and land against the wind?

Then why does SEA have 2 parallel runways? Land constaints?