Did a bit of math and geometry today (my old Geo teacher would be SO proud of me...NOT).

Looks like the big one's going to need to come in around 18 lbs to keep the same oz/sq ft wing loading of the little one. Since we're talking about a 77% increase in size of a 6 lb plane, that OUGHT to be doable. Obviously, the numbers don't translate dead on (i.e. I don't expect a 77% increase in size to translate to a 77% increase in weight), I certainly think keeping it within a factor of 3x is doable.

Anyway, that gives me a target weight, and also tells me that the BCMA 40 MIGHT be about the right motor for it...gonna be close, anyway...it's plenty for a 13 lb 3D plane, so it ought to give spirited but not unlimited performance in a 16-18 lb plane.

One nice thing...I don't have to make an engine decision until the entire plane is built, so I can get a good idea of what weight I'll be looking at.