Some students learn best when they can see aerodynamic principles in action. I'd really like to be able to show a student how a spin occurs.
Is there a way to make a paper airplane that will enter a developed spin?
I don't know if this will work for you, but I used to put little tears towards the body on the leading edge of the paper airplanes I made. Then I'd bend the leading edge of the wing down a bit to create a stronger airfoil. I'd do this simply to increase lift at low speed, kind of like slats. But I wonder, if you put a tear on only one side and adjusted it properly, perhaps you could make it so that one wing stalls out before the other?
Or, perhaps to be a bit more accurate, you could just go with tears on both sides but adjust one down further than the other. That way it's pretty apparent that on wing is developing more lift at low speed.