Becoming an architect and an airline pilot can be impossible. This is because airlines have a fixed and strict schedule that might not allow you to perform your architect duties. It can be possible with occupations that do not have tight schedules.
In theory you could be, but as has been mentioned, if you worked for a major airline carrier, you'd probably only have time to work with an occasional client as an architect. Unless you were like a part-time, or on-call pilot that only helped out on occasion.
But if you just want to learn to fly, you can be a pilot without working for a major airline. So it's up to you, whatever you want to do, and if you have the patience to go to school to learn both.