What are the two positions of the PROBE HEAT pushbutton?

What are the two positions of the PROBE HEAT pushbutton?

• A. AUTO
• B. AUTO or ON
• C. ON
• D. OFF

Answer: (B)

The PROBE HEAT control is a two-position switch that lets you choose automatic operation or continuous manual heating. In the Auto position, the pitot/air data probes are heated as needed by the aircraft’s ice protection logic—heat is applied automatically when icing conditions are detected or anticipated, helping keep airspeed and other measurements accurate while saving electrical power. In the On position, the heaters remain energized continuously, regardless of icing conditions, to ensure the probes stay clear in all circumstances, though this uses more power. The Off option isn’t a selectable position for this pushbutton in normal operation, which is why the two valid positions are Auto or On.

The PROBE HEAT control is a two-position switch that lets you choose automatic operation or continuous manual heating. In the Auto position, the pitot/air data probes are heated as needed by the aircraft’s ice protection logic—heat is applied automatically when icing conditions are detected or anticipated, helping keep airspeed and other measurements accurate while saving electrical power. In the On position, the heaters remain energized continuously, regardless of icing conditions, to ensure the probes stay clear in all circumstances, though this uses more power. The Off option isn’t a selectable position for this pushbutton in normal operation, which is why the two valid positions are Auto or On.