The build up of snow and ice can have significant issues for the performance of a helicopter. If icing is encountered, the shape of the rotor blade section can be changed by ice on the leading edge. This can increase the camber of the blade bringing forward the angle of attack at which the stall is reached.

The net result of ice accretion on the blades is a reduction of lift, as much as 30%, and an increase in drag, up to 40%, which affects the main rotor disk's track (making the contaminated blade to fly lower in comparison with the other blades) and reduces the performance of the rotor (reducing the power available).

This can be further compounded by assymetric shedding, resulting in significant vibration through the airframe and the result may be catastrophic. During lift-off, this could cause the helicopter to bounce and roll over or the Pilot to lose control.