I have not been doing much flight instruction work over the past few years, but I have noticed a couple common occurrences recently, both on flights and on various social media posts (Facebook, in particular). It seems a pilot will complain about the airplane not settling down, yet their approach speed is correct (such as 70 KIAS for an M20J).  Here are the things that come to mind when I hear this: Observation 1 - Idle RPM set too high.  I was flying with a client and he couldn't