Quoted:
Quoted:
PIO
Probably to start, but if you let the controls go to neutral position, won't the plane fly out of it?
Not necessarily with swept wing aircraft. Dutch roll...
and
As wing b is less swept in relation to the airflow, it produces more lift and creates a rolling moment since the lift is asymetric. As it reaches its critical AoA, the lift dissapates, the wing drops, and the other wing becomes less swept, and the process occurs in reverse. Slight more complicated than that, but thats the process in a nutshell.
A yaw damper uses a sensor and rudder to compensate and dampen these occelations. They are more pronounced at altitude, and thus high altitude flight in swept wing aircraft requires a yaw damp.
According to wiki, the Tu-154 doesn't have a yaw damp, using the reverse dihidreal effect of airfoil.
Quite a Russian solution to attempt to bypass the necessity of YD in highly swept wing airplanes.