An airplane will not fly without positive incidence or an airfoil that is not symmetrical. The positive may come in the form of up elevator trim, or a wing design that creates lower pressure on the top surfaces, but that effectively creates the same results of positive incidence. Right? Then there is lift created by a fuselage....or a powerful engine that is making a propeller fly that has an airplane attached to it. All this is very confusing and beyond my scope of knowledge!