When are all probes automatically heated?

• A. Weight off wheels
• B. On takeoff
• C. In flight
• D. On ice detection

Answer: (A)

The probes are heated to prevent icing from corrupting air data readings. The system is designed to switch to full heating automatically once the aircraft is airborne (weight off wheels). This ensures all pitot and air data sensors stay ice-free during climb and cruise, when accurate readings are critical. On the ground, not all probes are heated automatically to save electrical power and because the immediate icing risk is lower when the aircraft isn’t moving through supercooled air. Ice detection is a separate system and doesn’t by itself determine when all probes heat. So the moment you leave the ground, all probes receive automatic heat, making that the best answer.