When an aircraft flies in cold, moist air, especially at low altitudes, ice can form rapidly both on and behind the leading edge of aerofoils and other structures. The growth of the ice disturbs the local airflow and can radically alter the lift of the aerofoil and hence the handling characteristics of the aircraft. This phenomenon has caused a number of fatal accidents and loss of control events and is a problem that will intensify as increased pressures on airports mean that aircraft will spend much longer in low altitude holding patterns.

Large aircraft use hot-gases diverted from the engines to remove ice from flight-critical surfaces, while smaller aircraft sometimes use pneumatic boots which expand under pressure to shed the ice layers. These technologies are incompatible with future generations of air transport, in which composite materials will be used extensively. Furthermore, current ice detectors are insensitive, cannot distinguish between ice types and are not co-located with the safety critical zones.