When TAI is selected, the engine inlet is anti-iced but
the FAN CONE and BLADES will form some ice which can break off and damage the
FAN COWLING. They are subjected to ice build-up during descent and approach
through cold temperatures and humid air (clouds) especially near the center of
rotation at Flight minimum Idle.
To reduce the amount of ice build-up on the FAN BLADES, Approach Idle RPM creates higher centrifugal forces by an increased RPM with Flight Idle and TAI selected.
The image shows ice on the cone and the root of the blades which would be the result of our discussion.
