Chapter 4 - Preventative Measures and Deicing Procedures

Forced Air with Type II, III and/or Type IV Fluids

103.  These fluids are injected in the air stream, or applied over the air stream. The combination of anti-icing fluid and high speed forced air introduces some new concerns as well as some benefits. The anti-icing fluids must be handled correctly in order to retain their viscosity characteristics. One of the effects of injecting Type II & IV fluids into a high-speed air stream is that of shear. If these fluids are sheared significantly they lose some of their viscosity. The significance of this shear concern is that if the fluids are sheared excessively, the HOT values will not be valid for the fluid. It is anticipated that the concern about loss of viscosity will be addressed as forced air system design and operation are advanced.