I have encountered some unexpected icing in B-222, enough to cover the front window with rime ice (no windshield de-ice in that one!) and the nose and wings (wing stubs!) had 2cm (almost 1 inch) rime ice covering the leading edge.
This happened at about 2000´ca 10Nm from destination and the ice accumulation was over about a 5 min period.
I never noticed any unusual vibration or decrase in airspeed and upon landing at destination there was NO ice at all on the blades or tail section.
So I´m pretty happy about flying the B-222 in ice prone areas, although I try to avoid it at all costs.