Prop RPM during the approach.
I am going to move this discussion from the check list thread over here where we can discuss it as a stand alone subject.
I will first state that I do not increase prop RPM during the landing approach until I pull power off for the landing, then I push the lever/ s full forward. ( Or the pilot not flying does in a two crew device. )
Unless there is a need for increased RPM due to some unusual circumstance such as turbulence or airframe icing to name two possibilities I use the above procedure.
Here is why.
Increasing RPM on approach increases piston travel thus causing unneeded wear through friction in all piston engines.
Large piston engines are subject to reverse bearing loading caused by under squaring of power due to the airflow driving the engine thus causing reversing thrust loading of the bearings and counter weights.
When conducting an approach for a landing I am going down hill which requires less power than level flight, if I change my profile from descending to climbing I then select climb RPM followed by climb power I am hard pressed to think of a situation where there would not be time to smoothly perform these actions.
If a pilot gets into a situation where said pilot has to ram on take off power to salvage an approach or go around and does not have time to select the proper RPM for the power required it shows that said pilot was way behind the airplane thus displaying a serious lack of airmanship.
Having done tens of thousands of touch and go type flying using cruise RPM on the approach to power back for the touch down before increasing prop RPM, it has worked just fine for me.