Scale speed is intriguing. Time is linear in 'our world' so it stands to reason that a 1/4 scale model should fly 1/4 as fast as origional. However, scaling 'volume' and 'area' adhere to different factors. All of this added to Reynold's Numbers poses unreasonable demands to scale fidelity regarding flight characterisitics. This is one of those academic questions, for sure! The 'Moon Illusion' is one easily proved. Fullscale airliners appear to be flying v-e-r-y slowly but we all know that they are moving along at a good clip! The question of scale speed seems never resolved!