Under what condition should de-icing fluid not be applied to the wheel area?

The appropriate condition for not applying de-icing fluid to the wheel area is when the brakes are cool. De-icing fluid functions best when it is applied properly and allowed to adhere and function effectively on surfaces that require de-icing. If the brakes are cool, it could indicate that there is a risk of ice forming on or around them, and the application of de-icing fluid may not adequately address that issue—especially since the goal is to ensure that ice does not create hazardous conditions.

In colder temperatures, if the brake components are cool or cold, applying de-icing fluid may not result in the desired effectiveness, potentially allowing for ice formation or complicating the de-icing process. Hence, ensuring that the brakes are at the correct temperature prior to fluid application is crucial for safe and effective de-icing practices.

The other conditions—overcast weather, high ground speed, or taxiing on ice—do not directly relate to the temperature of the brakes and how de-icing fluid functions.