Wing Anti–Ice System
Positioning the WING ANTI–ICE switch to ON in flight:
- Opens both control valves
- Sets the stall warning logic for icing conditions.
Note: Stall warning logic adjusts stick shaker/minimum maneuver speed bars on airspeed
indications. FMC displayed VREF is not adjusted automatically.
Note: Stall warning logic remains set for icing conditions for the remainder of the flight
regardless of subsequent WING ANTI–ICE switch position.
Valve position is monitored by the blue VALVE OPEN lights. Duct temperature and thrust
setting logic are disabled and have no effect on control valve operation in flight.
