Which statement is true about anti-icing system automatic operation with respect to temperature limits?

Which statement is true about anti-icing system automatic operation with respect to temperature limits?

• A. There is no temperature limit
• B. There is a fixed 0°C limit
• C. There is a -18°C limit
• D. There is a 5°C limit

Answer: (A)

Automatic anti-ice operation is driven by icing conditions detected by the system, not by a fixed ambient temperature. The anti-ice system is designed to come on when needed to protect surfaces, and it will engage in AUTO whenever ice is detected or conditions warrant, within normal electrical and flight-crew controls. Since icing can occur across a range of temperatures (even near or below freezing in visible moisture), there isn’t a single temperature threshold that governs automatic engagement. That’s why the best answer is that there is no temperature limit. The other choices would imply a fixed temperature boundary, which isn’t how automatic anti-ice is intended to operate.

Automatic anti-ice operation is driven by icing conditions detected by the system, not by a fixed ambient temperature. The anti-ice system is designed to come on when needed to protect surfaces, and it will engage in AUTO whenever ice is detected or conditions warrant, within normal electrical and flight-crew controls. Since icing can occur across a range of temperatures (even near or below freezing in visible moisture), there isn’t a single temperature threshold that governs automatic engagement. That’s why the best answer is that there is no temperature limit. The other choices would imply a fixed temperature boundary, which isn’t how automatic anti-ice is intended to operate.