System to increase stability (SAS) is a type of control system, automatic flight. However, instead of putting the aircraft in a condition or predetermined path, etc. causes the correction damping oscillations to the optimal value, regardless of conditions and route of flight. System to increase stability, can cause the stability of the aircraft in one or multi-axis geared. For example, a common type, it Yau(Yaw Damper) is called that for sustainability and dispel mode, tumbling the Dutch(Dutch Roll) in the aircraft has Sweep back. and also some of these systems, along with system . Yau includes the sensor of Yau, etc., computer or amplifier and servo-(Servo-Actuator). This system uses the sensor. the start time, swing, tumbling Dutch, can cons. Computing the amount of displacement of the rudder, the vertical calculation, and then to the operator command corresponding to the control surfaces to move. Since all aircraft have wings (Sweep back), the mode Dutch-roll instability. from the system, it can be used.