ORIGINAL: buzzard bait

Scaling down does not change the relative effects of the tail arm and the stab area on pitch stability. The formula for the tail volume, which measures the stabilizing power of the stab relative to the wing, is as follows:

TV = (stab area/wing area) x (tail arm/wing chord)

All the units, squared and linear, cancel out. The resulting TV can be used to calculate CG. For any given design, the formula gives exactly the same result for small planes as it does for large ones....