Icing is significantly dangerous to all aircraft, even those with FIKI (flight into known icing) systems. It can result in significant performance reductions even with just a little ice.

All ice requires the following conditions:

  • Visible moisture (rain, being in a cloud)
  • The aircraft surface temperature must be below freezing

Without either, there’s no way for ice to form.

There are a few types of icing:

  • Structural Ice
    • Ice that forms on the structure of the aircraft.
    • Has the following subtypes:
      • Clear Ice: Incredibly dangerous. Heavy, hard and difficult to see and remove. Water drops freeze slowly and form as smooth sheet of solid ice. Forms close to the freezing point by large supercooled drops of water.
      • Rime Ice: Opaque, white, actually possible to see. Formed by small supercooled water droplets freezing quickly.
      • Mixed, as the name implies, is clear and rime ice formed together.
  • Instrument Ice
    • Ice which forms over aircraft instruments and sensors, such as pitot/static.
  • Induction Ice
    • Ice blocking the air intake for the engine, very similar to…
  • Intake Ice
    • Ice blocking the intake for the engine
  • Carburetor Ice
    • Forms in the venturi of carbureted engines.
    • Causes engine roughness and loss of power, as this prevents fuel from mixing with the air. Turn on carb heat to clear and prevent this.


Ice crystals caused by sublimation (water in the air freezing to the surface without transitioning to a liquid form) when both the temperature and dew point are below freezing.

Frost accumulates on the ground and should be swept off prior to flight.

If in doubt, just put the aircraft in a heated hanger until the frost melts off.

Last updated: 2021-11-13 22:33:55 -0800