Describe icing formation and characteristics.

Description should include the following concepts:

Two conditions are necessary for structural icing in flight—the aircraft must be flying through visible water such as rain or cloud droplets, and the temperature at the point where the moisture strikes the aircraft must be 0 °C or colder.
Supercooled water is in an unstable liquid state; when an aircraft strikes a supercooled drop, part of the drop freezes instantaneously. The latent heat of fusion released by the freezing portion raises the temperature of the remaining portion to the melting point. Aerodynamic effects may cause the remaining portion to freeze. The way in which the remaining portion freezes determines the type of icing.
The types of structural icing are clear, rime, and a mixture of the two and each type has identifying characteristics.

PLT274

Process/Skill Questions: