At least one Couper designed and installed a wing leveler for his 2-control Coupe. I'm blanking on his name at the moment - the fun gentleman with the gazillion fly-in patches on his coveralls and the hat with many pins and a windsock.
When I last saw him, he was working to add heading hold to his setup. He did the wing leveler using actuators from model aircraft. The actuator moved a small trim tab at the rear of an aileron. It's possible he had an actuator and tab on both ailerons but maybe not. If the system failed with full deflection, it was still easy to overpower the effect of the small tab and continue the flight. If I remember correctly, his wing leveler used air inputs from the left and right side of the plane blowing on a sensor. If the air blow was matched, the plane was straight. If it was asymmetrical, the plane was in a bank or turning. (This is going on a 20-30 year old memory of his explanation.) He liked showing it off. I kind of wanted one but never enough to bother making one and getting approval. Ed
