Hi Jim! 3-blades on RC aircraft might not do much, But on full scale they to do alot with efficiency. I posted before that mostly all of your WW2 planes had 3-bladed props and modern planes today,have variable pitch. The main reason was because the higher you fly, the less air there is. and you could adjust your pitch,to compensate. You can grab more air. just like in Pylon racing, Im shure everyone knows this,Take a 10 by 6 prop, The reasoning is that for every revolution you move 6" forward,I gues on a calm day. But we never have that.HA. Nice to here from you JIM. How have you been?