These autonomous systems prevent a wide range of problems associated with ice buildup, such as increased airframe stress, transmission damage and rotor shedding, which could potentially lead to impact events. They also prevent the need for fatigue inspections that are required after incidents of ice-induced vibration. They feature sensors that detect icing, a heating power distribution unit, heating elements or mats for airfoils, and a controller unit. In contrast to the autonomous ice detection and prevention systems, manual ice detection and protection systems require the pilot to manually activate a system in response to an alarm, or to elect to ground the aircraft.