Boeing 737 NG Systems Review
Forward Overhead Panel  700/800/900
Display Selector
Wing and Engine Anti - Ice Panel
WING ANTI–ICE Switch

OFF – Wing anti–ice control valves are closed.

ON (in the air) –

  • Wing anti–ice control valves are open.

  • Stick shaker logic is set for icing conditions.

Note: Stick shaker logic remains set for icing conditions for the
remainder of the flight, regardless of subsequent WING ANTI–ICE
switch position.

ON (on the ground) –

  • Wing anti–ice control valves open if thrust on both engines
    is below takeoff warning setting and temperature inside
    both distribution ducts is below thermal switch activation
    temperature

  • Control valves close if either engine thrust is above takeoff
    warning setting or thermal switch is activated in either
    distribution duct. Switch remains ON

  • Switch trips OFF at lift–off.