Originally Posted by Uncle Bose
It wouldn't work like a boat. You need the bank to develop the centripetal force (horizontal component of lift) which causes the airplane to deviate from a straight path.
I am very aware of the question and the answer. I tried to keep the response SIMPLE to avoid a dissertation on physics. Airplanes will turn without ailerons, and if you want to get into physics we can go there but don't plan to overcomplicate the basic question.