James Bay Daze:
Bell 47 with blade ice from flight of 2-3 minutes Ice fog -
206's A + B - with particle separator needs snow deflectors.
206's A + B - with no particle separator needs reverse scoops.
206 L (C-20B)- particle separator had to be removed and reverse scoops installed.
I recall at least 2 206s with no particle separator and no scoops flaming out in heavy snow.
( No not me )
205 - damned if I remember exactly - no scoops or deflectors - can't remember about anti-ice but we used to fly around in some very reduced vis in snow with no adverse effect however.
212 no scoops, no deflectors, no worry - durn things do not have inlet anti-icing - gotta love P+W - snow didn't hack the 90 deg turn down into the intake.
AS 350D carry on as normal
AS 350B I recall we had particle separators all year.
AS 355 straight intakes no Particle Separator - I think there was a limit if you had a particle separator installed but only flew TwinStars with particle separators installed in Africa where it did not snow much.
Long ago and far away now but that's how I recall the scenario.