Abstract: A tethered aeroform balloon having an inflated toroid tail structure secured to the balloon hull by means of a plurality of rope lines for supporting the drag forces and the weight and steering forces of the tail structure. The inflated tail structure has a substantially symmetrical air foil section with support diaphragms secured inside the tail structure. The tail structure is inflated by an electric motor powered fan supported on the tail structure. A pressure switch prevents over inflation of the tail structure. A check valve prevents the escape of air from the tail structure when the fan is not running.