What Are The Types Of Icing?

For pure water to freeze in the atmosphere, it must reach a temperature of -40 degrees Celsius. However, water in clouds where water vapour is below freezing to -40 degrees may have a mix of icing and supercooled water.

Supercooled water upon contacted with a surface (such as an airplane), may have a chance to instantly freeze and create ice. There are three types of icing: rime, clear, and mixed. The type of icing largely depends on the size of the supercooled water droplets and the temperature. 

Rime 

• Rough, milky, and opaque ice
• Formed by small supercooled droplets
• Jagged, rough texture can make an unpredictable shape of an airfoil's chamber
• Most common
• -15°C to -40°C

Clear

• Glossy, clear, or translucent 
• Formed by large supercooled droplets
• Denser than rime ice, heavier
• Change the weight of the airfoil
• Difficult for pilots to see and recognise due to it being clear
• 0°C to -10°C

Mixed

• Combination of Rime and Clear
• -10°C to -15°C

Hazards

• Can reduce lift
• Increase drag
• Raise stall speed
• Compromise aircraft performance