Boolean operations work best when the object being union/subtracted is a SOLID. Solids are fully enclosed surfaces, with no holes. You can check if an object is a solid by selecting it, then using the ANALYZE_MASS PROPERTIES_VOLUME function. That will tel you if the surface is open or closed (surface or solid)
You should try to use the CAP PLANER HOLES function to close up the ends of that wings before trying to boolean, or (if the ends are not planar) split it with some rectangular surfaces, then cap the ends.
Also, without some kind of intersection between the objects (touching each other), the boolean operations will not work.
I would draw the "cube", and then BOOLEAN SUBTRACT the solid wing from it.