Thomas Coupling,
As a mil pilot I was under the impression that rotor and airframe icing conditions are defined as cloud or fog within the temperature range 0 deg C to 30 deg C true, WHEN THE VISIBILITY IS LESS THAN 1000 METRES. Visibility reduction due to snow alone does not constitute an icing condition.
There are different rules for icing conditions (no go) and for flying in snow (dependent on viz/temperature)
