Which conditions will activate the de-ice system for propellers?

The de-ice system for propellers is designed to prevent ice accumulation that can adversely affect performance and safety. It is activated under specific temperature and altitude conditions, which correlate with known ice formation scenarios. In aviation, ice tends to form when temperatures are near or below freezing, particularly during flight in moist conditions. The system utilizes these specific parameters to optimize its operation, ensuring that it activates at the right moments to maintain propeller efficiency and safety.

The other conditions, while they may relate to various operational scenarios, do not follow the precise criteria necessary for the activation of the de-ice system. For instance, the temperature being above -30 degrees does not apply as ice can still form effectively at higher temperatures in certain conditions. Prolonged flights over water are not a direct trigger for de-icing mechanisms, although they can influence overall aircraft performance. Flap position impacting the activation is also misleading, as the system relies more on environmental factors rather than control surface position. Hence, the specific temperature and altitude parameters that define the activation thresholds for the de-ice system are critical for maintaining optimal propeller performance.