Chapter 3 - Deicing/Anti-icing Fluids

Type III Fluids (TBA)

34.  Type III is a thickened FPD fluid that has properties that lie between Types I and II. Therefore, it provides a longer holdover time than Type I but less than Type II. Its shearing and flow off characteristics are designed for aircraft that have a shorter time to rotation making it acceptable for some aircraft that have a Vr exceeding 60 knots.

35.  The SAE has approved a specification in AMS 1428A for Type III anti-icing fluids that can be used on those aircraft with rotation speed significantly lower than the large jet rotation speeds, which are 100 knots or greater. Type III may be used for anti-icing purposes on low rotation speed aircraft, but only in accordance with aircraft and fluid manufacturer's instructions.