A question for the pilots out there.
I was in a Q400 today right next to the LH wing (at about 19000 ft if I heard the F/O properly) when I noticed ice both around the intake(?) just behind the props but more curiously in the centre of the prop (excuse complete lack of technical knowledge) and "growing" (along the cone section rearwards) as we travelled, until the cone section in question went almost entirely white.
This isn't something I've noticed on the Q400 or other dashes before, although most of the flight (Gladstone to BNE in Oz) was in cloud, so icing would be expected I guess. I was just curious how the rotating centre of the propeller array, at such high revs, could still ice up and was also interested as too how much icing could occur before it became a concern.
