The purpose of the tests was to evaluate a series of control devices proposed as aerodynamic controls for wind turbines. This application imposes airfoil design constraints of large thickness and high angles of attack. Primary purpose of control is to slow or to stop the turning of a wind turbine rotor, requiring negative torque to be produced over much of the rotor span. For an untwisted, zero pitch, rotor this requirement means that negative CS must be produced at most angles of attack. Reflection-plane tests of an NACA 23024 airfoil were conducted in the WSU 7 x 10 ft. wind tunnel. The airfoil was equipped with a series of devices, including spoilers and deflector-ailerons. Force results are presented in terms of leading-edge suction force , normal force (CN), and pitching moment (CM), as well as wind-axis forces of lift (CL) and drag (C0). The results show that it is possible to design retractable deflector-aileron control surfaces which will produce, when extended, negative leading-edge suction over wide ranges of angle of attack. Best angle of deflection of the deflector-ailerons tested is 90°. Increasing Reynolds number tends to increase values of CS. A gap at the surface hingeline permitting flow of air between upper and lower surfaces minimizes Reynolds number effect on