scaling down or up -- is a real trap for most modelers.
scaling down -- you usually can't stay light enough to get equivilant performance
scaling up - typically you quickly run out of power
for example: most 40% aerobatic types are never too heavy to fly well but power is never excessive
scaling down to really small stuff -like a 30" span - power remains ok but wing loading is almost always way too high for slow flying.
if only the air could be scaled to match the model.
from the first Wright Bros thing - getting enough power has alwas been a problem
ALL of the powered aircrft since then have only improved as better powerplants became available
all of the work on airfoils for them has been done in order to make the weight work with the power available.