As far as I am aware the Bus rat.. 320/330 has the oil warming circuit to keep the important bits toasty when its called into action (solenoids and valve block).. as for deicing the blades.. there is none.. however inside the hub there are carbon blocks which rub on the inside of the hub when it is rotating keeping the hub and pitch change/governing mechanism warm. I guess this would extend to the blade root but the cooling effect on the outer part of the blades would not allow the hub heat to get there I presume.. As long as the blades don't liberate (thankfully those days are gone) ..It should be ok