Fred and Clancy:
Maybe I am missing something, but this math escapes me. We are not dealing with the area of the circle, but rather with the distance around the circle. So in the 1/8 scale example that was used, 1" of representation on the model represents 8" on the real plane. This would relate to the distance of the wingspan (model x 8 = the real plane) AND the distance of the fuselage centerline (model x 8 = the real plane). So, when the model moves forward one model length, in scale length it has moved forward 8 model lengths (model x 8 ). When that model moves 1 MPH, in scale speed it has moved 8 MPH (model x 8 ). When it moves at 30 MPH, in scale speed it has moved 240 MPH. Again, this assumes the 1/8th scale model. It all changes with a different scale. What am I missing? At my age, it is easy to miss things.
Jim Fruit