What happens to TAT heaters when the airspeed drops below 45 knots while landing?

When the airspeed drops below 45 knots while landing, the TAT (Total Air Temperature) heaters become inactive. This is a designed safety feature to prevent overheating and potential damage to the sensors as they are unnecessary at lower speeds, where accurate total air temperature readings are less critical for performance and safety. At higher speeds, the heaters are essential for ensuring the accuracy of temperature readings, especially in conditions where icing might occur.

When the aircraft slows down to a speed below 45 knots, maintaining heat for the TAT is not required, leading to the heaters being deactivated to conserve energy and reduce wear on the system. This helps in preserving the overall functionality of the sensors and ensuring that they are ready for use when needed at higher speeds.