The Challenger 601-604 must have some sort of a supercritical icing vulnerability.
There have been at least 3-4 icing related accidents on it in the last very few years.
I am sure that Challenger pilots are just as professional as pilots of Beech, Citations, Hawkers, Falcons , Gulfstreams, Learjets, so this has to be an airplane weakness. Specially when you take into account total airframes of all the other types together versus the Challenger.
Statistically it doesn't seem to add up.
Not much wing out there (and no slats) for a big fattie that it is.( not an expert)
I guess all you Challenger pilots will have to be EXTRA carefull out there in the winter!