ATA 27 - FLIGHT CONTROLS

• In normal operation, the roll function of the ailerons is achieved through the ELAC 1 and the associated servo controls in active mode, the ELAC 2 being in standby and its associated servo controls in damping mode.

• The trim actuator, the yaw damper servo actuators and the travel limitation unit are normally controlled by the Flight Augmentation Computer (FAC) 1, the FAC 2 being in standby.

• In normal operation the elevators are controlled by the ELAC 2 and the associated servo controls in active mode, the other computers being in standby and the servo controls in damping mode.

• THS An overriding mechanism gives the priority to the mechanical control over the electrical control.

• EFCS automatically reverts from normal law to either alternate or direct law.

• Sideslip target computation is performed by the FACs.

• One aileron (operational at all speeds) and four spoilers ensure roll control on each wing -When the autopilot is not engaged, the Elevator Aileron Computer (ELAC) calculates the yaw damper order with the normal law.

• If both ELACs fail, only the dutch roll damping (alternate law) is computed by the Flight Augmentation Computer (FAC) using the ADIRS data.

• The rudder travel limitation is computed by the FAC and sent to the Rudder Travel Limiting unit.

• The FACs also control the trim actuator in AP mode.

• If both FACs fail, the rudder travel limitation value is frozen immediately

• Signal from SFCC when slat extend system go back to low speed!

• The yaw damper servo-actuator orders are added to those of the pilots up to the maximum travel that the TLU permits.

• One of the two servo-actuators is active, the other remains in standby (bypass mode).

• In case of total computer failure, the actuators will be in centering mode as long as hydraulic power is available.

• In the normal configuration, the inboard servo control is in the active mode.

• Normal speed with two hydraulic systems available is 2 / sec.

• If the roller is in position “TRIPPED BY VIBRATION”, reset the red pop-out: Push the roller with a tool, for example a small screwdriver, in the reset position.

• If the roller is in position “TRIPPED BECAUSE OF ‘NO BACK’ WEAR”, replace the THS Actuator.

• The IPPU, which is installed on the PCU, supplies flap position data to the flight data recorder and the Flight Warning Computer (FWC).

• An APPU is installed at the end of the transmission system in each wing.

• Each flap-attachment failure detection sensor sends a signal to one of the two Landing Gear Control and Interface Units (LGCIU).

• The circuit can only be set back (WTB) (reset) on the ground through the Centralized Fault Display System.

• The Air Data/Inertial Reference Units (ADIRU) supply corrected angle-of-attack (alpha) and computed air speed (CAS) data to the SFCC.(retraction not possible if AOA is more then 8.5 and CAS is less then 148 KTS).