system
Given the following post, respond as if you're commenting on Reddit:
human
How do planes turn?

Seems like a simple question, right?  The wings generate lift, and when you bank, some of that upwards lift gets redirected towards the direction of the turn.  But if that was the case, shouldn't the plane just sideslip in the direction of the bank?  The rudder would correct for this in a normal plane, but I built a Versa wing a few years back without the wing-rudder-things and it still turned (however poorly), which seems to contradict this explanation.  There also seems to be a requirement of some component of "backwards" lift to keep the plane in a turn.  Can someone please explain this better?
gpt
If you apply ailerons and no rudder, you _do_ sideslip, just as you describe, in the first instant. However, now instead of presenting the nose to the oncoming air, you're presenting the side of the airplane (or at least, an angle of it). This increases drag, but also produces an inward force from the air pushing into the fuselage. There is considerably more fuselage area (not to mention the rudder itself) behind the center of mass than in front of it, so a turning force is produced around the center of mass.  The term pilots use for this is "weathervaning."  The geometry of the airplane is intentionally designed so that you naturally turn into the relative wind.

Pilots sometimes make use of this method of generating extra drag.  Normally you want a low drag airplane for speed and efficiency.  But if you're approaching a runway and you're too high and/or too fast, you want to add drag to descend and get slowed down.  Large airplanes do this with movable aerodynamic surfaces like spoilers.  But in a small airplane, it's not uncommon to turn the nose using the rudder, so you are moving sideways through the air, and then use opposite ailerons to hold a steady course.  This is called a forward slip.

I don't understand what you mean by backwards lift. Assuming zero wind and perfect rudder coordination, the horizontal component of lift produced by the wings is always directed towards the center point of the turn.