The Ercoupe has the traditional aerodynamic control surfaces that could control pitch, roll, and yaw if connected to conventional controls but without the rudder pedals the pilot has only two axes of control, pitch and "turn" (coupled yaw/roll). The effect is the same as a Quicksilver or Sky Pup without any form of roll control surfaces and just a rudder, but Ercoupe's coupled controls reduce the initial skidding before dihedral effect takes over in a turn.

Quote Originally Posted by CHICAGORANDY View Post
As I understand it the Ercoupe is a three-axis airplane, it links the rudder and ailerons to the control wheel instead of having rudder pedals (an optional accessory)