This report presents the results of flight tests made on five different lateral control devices that appeared adaptable to wings fitted with full span flaps: controllable auxiliary airfoils (airfoils mounted above and forward of the leading edge of the wings), external ailerons (airfoils mounted above the wing and slightly forward of its maximum ordinate), upper-surface ailerons (similar to split trailing-edge flaps except that they constitute the upper surface of the wing), ailerons that retract into the wing when in neutral, and narrow-chord conventional ailerons in combination with a special type of split flap that retracts into the under surface of the wing forward of the ailerons. The devices were tested on a small parasol monoplane. E...