Wind tunnel tests were conducted at full-scale Reynolds numbers on a one-half scale model of the semispan of a cessna 170 wing, equipped with suction and blowing slots for boundarylayer control. The effect of boundary-layer control by suction and blowing was determined upon lift, drag, aileron hinge moment, rolling moment, pitching moment, and yawing moment. General studies were made of the effect of boundarylayer control upon downwash and flow pattern as well as structure of the circulation around the wing. The aerodynamic characteristics of the wing, together with the air quantities required for boundary-layer control, were studied from The standpoint of practical design application. Values of maximum lift coefficient up to 2.93 were secured with total drag coefficients which were considerably less than those which would be predicted by conventional induced drag theory. Aileron effectiveness was improved sufficiently to increase PB/2V values by ratios of 2.5 over the value which could be secured without boundary-layer control. Pitching moments about the aerodynamic center increased to values of -.45, but downwash studies indicated that the angle of downwash increased sufficiently to compensate for the pitching moment by increased down flow at the tail group. Measurements indicated that the strength of the circulation about the airfoil profile was increased over both the blowing and suction portions of the wing. The effect of this system of control appears not to be limited to the boundary layer only, but to extend to the entire circulation pattern of the wing. The results appear to be quite applicable for design use and are now being studied on a particular application.