What is a possible indication of the need for cowl anti-ice?

Cowl anti-ice is a system designed to prevent the accumulation of ice on engine inlets and other critical areas of the aircraft during flight in conditions conducive to ice formation. The presence of an ICE message displayed on the cockpit instruments is a clear indication that icing conditions are detected.

When the ICE message appears, it signifies that the aircraft is operating in an environment where ice may form, and the cowl anti-ice systems should be activated to ensure proper engine performance and safety. This proactive measure helps maintain engine efficiency and prevents ice from obstructing airflow to the engines.

While the other options could be related to engine performance or temperature readings, they do not provide a direct and unequivocal signal about the necessity for activating the cowl anti-ice system. The ICE message is specifically designed to alert the crew to the potential icing condition, making it the most relevant indicator for ensuring the aircraft operates safely in such environments.