Critical Surface Contamination

Question 1

What is TYPE I Fluid?

Answer 1

A de-icing fluid, used to remove existing ice. It will melt the ice off and as long as the temp is not colder than the rating for the glycol they are using, the melted ice will run off the wings.

Type 1 provides some protection against water refreezing but not much against further contamination

Question 2

What is TYPE II Fluid?

Answer 2

Designed more for anti-icing. More viscouse than Type 1 and stick to the surfaces and absorb precipitation while on the ground.

During takeoff, these become less viscous and flow off surfaces

Question 3

What is a TYPE III fluid?

Answer 3

Something between type I and type II. Still in development kind of.

Type II shears off surfaces (Vr) at 100kts, Type III would be lower, around 60kts

Question 4

What is Type IV fluid?

Answer 4

Meets the standards of Type II but have a much longer holdover time. Has a Vr (shear off speed) above 100kt

Dyed green so it doesnt get mistaken for ice.

Question 5

What is ‘holdover time’ in terms of de-icing fluid?

Answer 5

The amount of time a fluid provides a beneficial effect.
Holdover time is calculated at the start of the final application until the time when the fluid is no longer effective.

Times are affected by many factors, including:
* the water to fuild mix ratio
* relative humidity
* winds
* temperature, type of fluid used, etc