Jim, I understand how P effect is supposed to work, I just don't see how it applies to our models. Most pattern airplanes sit at rest maybe 15 degrees but the tail rises pretty darned quick. After the tail rises there is still rudder input required to the right. During flight our light models react to inputs very quickly and are flying quite fast for their size. As a result I tend to beleive that for the most part the airflow hitting the prop is almost always at 90 degrees to the prop disk. The only time I see this changing is during final approach to touch down. Even then unless there is a cross wind I don't hold rudder to the right during flare to counteract the P effect created from flying 10-15 degrees nose up from flight path. Granted at that point we are at very low power setting. Have a look at the first part of this video. You can clearly see rudder input on the take off roll. You can also see it being tapered off as the torque curve flattens out as speed builds
https://www.youtube.com/watch?v=GQTLS6l28fo