Ice forming on an aircraft can pose significant hazards and has been the cause of many accidents over the years.
Ice forming on an aircraft will:
This significantly reduces performance, with the aircraft possibly not being able to maintain altitude or becoming uncontrollable.
Ice buildup on engines, propellors and internal components can:
This can leads to reduced power output or even complete engine failure.
As a general rule, external airframe ice only occurs when flying in visible moisture (cloud, rain, fog etc.) with temperatures between 0°C and -20°C. Generally, ice does not form on the airframe in temperatures below -20°C. Instead, it will already be frozen ice pellets that ‘bounce’ off the airframe.
However, other forms of icing (particularly piston engine icing) can occur above 0°C and you will need an understanding of the different icing types.