Constrictor, You are reading too much into this. I built mine yesterday and didn't really care what side is up or down. I Just put the 2.5 in wing tip to wing tip balsa sheet on one side and the hatches on the other. The wing is a doubled tapered, no dihedral wing. Pull it off the table and flip it over and you will see it's the same on both sides. Just pick what side you want to be the top.