My old coach Harry Roe had a great name for most of this type of discussion. He'd call it "aerodramatics". It's simply amazing how often someone who says, "This is an absolute truth in trimming" is so often incorrect. Now I'm seeing that downthrust is a terrible evil. I sure am glad for these forums, because I didn't know that for the 37 years I've been trimming pattern models.

There are so many trim issues caused by the use of a single propeller that until you experience a model without all those issues you really don't know what you're talking about. I sure wish Harry was still around to see what he pushed me to try back in 1982. I didn't have the engineering skills to make the Contra unit I built back then work well enough. But at least I can experience it now.