NEMP protection - ACJ and BBJ Considerations

[Airbus Instructor]

A320 FBW Systems

Gentlemen,

Find below some information about the A320 FBW systems.

• The RAT can be extended by two ways:

1. Automatically; in case of loss of both AC BUSSES with A/C in-flight and speed > 100 KTS, where the EMER GEN will automatically activate to supply the ESS busses and save battery life.
2. Manually, by pushing one of two push buttons, (RAT MAN ON) on HYD panel OR (MAN ON) on the EMER ELEC panel, the last one will not only extend the RAT, but also will activate the emergency generator to supply the ESSENTIAL Busses; the two push buttons will supply BATT power to two different solenoids that will unlock the RAT uplock and allow a spring to extend the RAT.
3. The logic on the A330/A340 is almost similar; the only Airbus that uses a cable to extend the RAT is the A300 and the A310.

• The A/C flight control system is totally hydraulically operated, so HYD pressure should be available to have control.

• In case of total ELEC failure provided HYD PRESS is available, the A/C can be controlled using the STAB trim wheel for PITCH control and using the rudder pedals for YAW/ROLL control. Now in the configuration, the A/C is fully controllable and can be maneuvered for landing.

• Landing gear is controlled electrically, but a mechanical backup is provided to mechanically unlock the Doors/Gears uplocks and take them down.

• Wheel brakes are electrically controlled, but a manual backup is provided as well, (of course HYD should be available)

Sorry for the long answer but I hope this gives better understanding of the A320 System.