Icing Severity Factors MET

Two main features of the aircraft affect the severity of icing: speed and the shape of the leading edge.

Speed is the easier one to understand: the faster you are going, the more supercooled water droplets you will hit and hence the greater the severity of the icing. Faster speed means worse icing.

For wing shape, the answer is slightly less intuitive. A broader edge will cause a thicker boundary layer where air and the droplets are forced away from the wing and so the droplets cannot hit the wing. You may already be familiar with this boundary layer concept from Principles of Flight. A sharper wing will not have such a boundary layer, and so will be hit by more SCWD, and so have more severe icing. Sharper wing means worse icing.