Standby Hydraulic System  (Contd.)

Positioning the ALTERNATE FLAPS master switch to ARM:

  • Activates the standby electric motor–driven pump.
  • Closes the trailing edge flap bypass valve.
  • Arms the ALTERNATE FLAPS position switch.
  • Allows the standby system to power the leading edge flaps and slats and thrust
    reversers.

Automatic Operation

Automatic operation is initiated when the following conditions exist:

  • Loss of system A or B, and
  • flaps extended, and
  • airborne, or wheel speed greater than 60 kts, and
  • FLT CONTROL switch A or B Hydraulic System ON
OR:
  • The main PCU Force Fight Monitor (FFM) trips. (Modified rudder- installed)

Automatic operation:

  • Activates the standby electric motor–driven pump.
  • Opens the standby rudder shutoff valve.
  • 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)