So you are saying that you can not fly an airplane inverted because it has dihedral? Really?

Because I have yet to see the model that will not fly inverted, regardless of dihedral or airfoil when it has adequate power. Most models have more than enough engine to maintain sustained flight, with enough excess to make turns and fly around the field.

This includes all models that have ailerons and includes all that just have rudder and elevator for flight controls.