Impulse Coupling – is located in the Magnetos, it assist in engine starting. It momentarily rotates magnetos to assist engine starting.
Wash in – is when angle of incidence of wing tip is lower than wing root.
Wash out – is when angle of incidence is higher than wing root.
Dihedral – is when the Wing tip is of higher angle of incidence than wing root. It increases Lateral Stability.
Anhedral – is when wing tip is of lower angle of incidence than wing root. It decreases Lateral Stability.