The aircraft I fly is "cleared for flight in light icing conditions". Attached to this are various items of equipment that must be fitted and working. Included in this list of items is an ice detector. The definition of light icing is based on the rate at which ice accretes on the detector. In other words the icing clearance is type specific and is no doubt determined after extensive trials. Moreover, there are operational procedures that are applied during flight planning that allow one to escape from icing conditions beyond the capability of the aircraft.
Very practical.
Icing conditions are assumed when there is a) Freezing rain (get another cuppa, remain earthbound), b)OAT less than 0 deg C with visible moisture/flight viz less than 1000m (in effect IMC).
I assume the 215 has a permanent warning of ice simply because the met in the UK changes so quickly, can be very localised and is effected by our very varied topography. The 215 is simply too generalised to be more specific about icing. I suspect it is more aimed at the VFR GA community.
Last edited by Droopystop; 25th March 2006 at 08:45.