Airspeed
I just fly my own plane, a B36TC Bonanza, single pilot, and stay out of icing conditions altogether. But on any approach, IFR of Visual, airspeed is probably the thing I monitor most. And I know how fast the plane should be going at a given power setting and configuration, so if my rules of thumb don't add up, a great big red flag would start waving in my mind. In the approach phase of this flight, I didn't see any comments suggesting that IAS was being monitored at all, or did I miss something?
Is that normal in a plane with a crew? I always imagined you would be calling it out, just as on take off.