Roll creates counter rotational forces on both starboard and port wings whilst also generating such forces at the empennage. These opposing rolling moment effects have to be overcome by the aileron input in order to sustain the roll rate. If the roll is stopped at a non-zero roll angle the formula_119 "upward" rolling moment induced by the ensuing sideslip should return the aircraft to the horizontal unless exceeded in turn by the "downward" formula_120 rolling moment resulting from sideslip induced yaw rate. Longitudinal stability could be ensured or improved by minimizing the latter effect.