I read the interesting article Flying by Peter Garrison, Camel Trimmer. In it he refers to an "aerodynamically balanced rudder" . In Engineering Aerodynamics, Diehl, 1939, Diehl specifies that control surface should be aerodynamically underbalanced. Can someone help me understand what aerodynamic balancing is? thanks.
Here is a link to a short video that is a simplified explanation of a somewhat complicated concept with illustrations including the four basic ways an aircraft designer can address aerodynamic balancing.