Originally Posted by Mitragorz

Va INCREASES with weight!


This is how I've always thought about it. Va is the highest speed at which you can have maximum deflection without hurting the airplane.

A lighter airplane is more "flickable." It responds faster to control inupts and is more easily overloaded. A lower airspeed is required to prevent the airplane from "flicking" too fast and putting too much stress on the airframe.

A heavier airplane would be more "sluggish," it won't respond as quickly to control inputs. Instead of jerking into a roll like a light airplane would if you went full deflection, the heavier airplane would do more of a slow roll with full deflection, allowing for a faster airspeed to be used with that full deflection.