Standby Hydraulic System

The standby hydraulic system is provided as a backup if system A and/or B pressure is lost.
The standby system can be activated manually or automatically and uses a single electric
motor–driven pump to power:

  • Thrust reversers.
  • Rudder.
  • Leading edge flaps and slats (extend only).
  • Standby yaw damper.

Manual Operation

Positioning either FLT CONTROL switch to STBY RUD:

  • Activates the standby electric motor–driven pump.
  • Shuts off the related hydraulic system pressure to ailerons, elevators and rudder by
    closing the flight control shutoff valve.
  • Opens the standby rudder shutoff valve.
  • Deactivates the related flight control LOW PRESSURE light when the standby rudder
    shutoff valve opens.
  • Allows the standby system to power the rudder and thrust reversers.
and
  • Illuminates the STBY RUD ON, Master Caution, and Flight Controls (FLT CONT)
    lights. (Modified rudder- installed)