That’s hard to say without more information, many different types of “balsa wood planes” have been made, from simple rubber band airplanes with thin, uniform thickness, flat or slightly curved wings, to high performance sailplanes with high aspect ratio wings with sophisticated asymmetrical air foils, to powered aerobatic aircraft with relatively short wings with symmetrical airfoils.
That’s hard to say without more information, many different types of “balsa wood planes” have been made, from simple rubber band airplanes with thin, uniform thickness, flat or slightly curved wings, to high performance sailplanes with high aspect ratio wings with sophisticated asymmetrical air foils, to powered aerobatic aircraft with relatively short wings with symmetrical airfoils.