A speed brake apparatus reduces the airspeed of an aircraft by increasing aerodynamic drag. First and second brake panels are located on opposite sides of a portion of the aircraft, such as the fuselage, and are adapted to swing outward about a downstream hinge axis into deployed positions extending into the air stream. The panels are controlled by an operating device that includes a linear actuator. The actuator moves an operating head connected to a pair of toggle assemblies to convert linear movement of the operating head to the deployment and retraction movement of the brake panels.