The horizontal or vertical aerodynamic wing surfaces that provide aircraft stability and longitudinal balance in flight. Horizontal and vertical stabilizers (fins) are similar to the aircraft wing in structural design and function of providing lift at angle of attack to the wind. However, stabilizers are not required to supply lift to overcome aircraft weight during flight, and when the wing-fuselage center of pressure is behind the aircraft center of gravity, the aerodynamic load on the horizontal stabilizer may be downward.