What precaution should be taken when using Type IV fluid?

The use of Type IV de-icing fluid requires careful consideration of holdover times because, compared to Type I fluid, it has a slower performance in terms of its effectiveness at preventing ice and snow accumulation. Type IV fluid is designed for long-lasting protection and is typically used in colder temperatures or when the aircraft will remain on the ground for an extended period. It is crucial for operators to understand how long the Type IV fluid will remain effective in the specific weather conditions to ensure that the aircraft remains free of ice and snow before takeoff.

Recognizing the holdover time allows for better planning and safety, ensuring that the de-icing process is effective throughout the aircraft's time on the ground, especially if conditions change or if the aircraft is delayed. This knowledge is vital for maintaining aircraft safety and performance during winter weather operations.