pedal input the order from the Yaw Damper function. This deflection is limited by the RTLU (Rudder TravelLimit Unit) for structural considerations. The Rudder trim merely moves the pedals.Role ofthe Yaw Damper on FBW aircraft: A320 The Yaw Damper functions are achieved by the ELAC whenhandflying the Aircraft: Dutch Roll Damping and Turn Coordination Lateral Control Law objectives (eg: = f(rudderpedal), engine out ...) The FAC transmits the ELAC rudder deflection orders tothe Y/D actuator and achieves the Rudder Travel Limit function.OperationalConsequences On most commercial A/C, the rudderMUST NOT BE USED: to induce Roll, to counter Roll induced by any type of turbulence, for turn coordination (exceptionally in Direct Law,with a double hydraulic failure where YD is lost). On most commercial A/C, the rudderIS ACTUALLY USED ONLY: during T/O and LANDING Roll, in case of Engine Out, as a yaw corrective action, during the last phase of a flare with crosswind fordecrab purpose. On most commercial A/C: there is no need to act on the rudder abruptly, in case of failure leading to a loss of TLU, the rudderis to be used with care, as per ECAM, there is no roll control restriction with an engine failed.AircraftAirbus 320-216 Flight Controls Laws AIRBUS FLIGHT CONTROL LAWS High AOA Protection Load Factor Limitation Pitch Attitude Protection NORMAL LAW High Speed Protection Flight Augmentation (Yaw) Bank Angle Protection Low Speed Stability Load Factor Limitation ALTERNATE LAW High Speed Stability Yaw Damping Only Load Factor Limitation ABNORMAL ALTERNATE LAW w/o Speed Stability Yaw Damping Only DIRECT LAW FLIGHT CONTROL LAWS SUMMARY NORMAL LAW Normal operating configuration of the system. Failure of any single computer does not affect normal law. Covers 3-axis control, flight envelope protection, and load alleviation. Has 3 modes according to phase of flight. Ground Mode Active when aircraft is on the ground.Direct proportional relationship between the sidestick deflection and deflection of the flight controls.Is active until shortly after liftoff.After touchdown, ground mode is reactivated and resets the stabilizer trim to zero. Flight Mode Becomes active shortly after takeoff and remains active until shortly before touchdown.Sidestick deflection and load factor imposed on the aircraft are directly proportional, regardless of airspeed.With sidestick neutral and wings level, system maintains a 1 g load in pitch.No requirement to change pitch trim for changes in airspeed, configuration, or bank up to 33 degrees.At full aft/fwd sidestick deflection system maintains maximum load factor for flap position.Sidestick roll input commands a roll rate request.Roll rate is independent of airspeed.A given sidestick deflection always results in the same roll rate response.Turn coordination and yaw damping are computed by the ELACs and transmitted to the FACs.No rudder pedal feedback for the yaw damping and turn coordination functions. Flare Mode Transition to flare mode occurs at 50' RA during landing.System memorizes pitch attitude at 50' and begins to progressively reduce pitch, forcing pilot to flare the aircraftIn the event of a go-around, transition to flight mode occurs again at 50' RA. Protections Load factor Limitation Prevents pilot from overstressing the aircraft even if full sidestick deflections are applied.Attitude ProtectionPitch limited to 30 deg