I'm not sayign I dont think AutoCad is worthless at all - but you wont be able to do 3d modeling and analysis.
I just think a 3d modeling program would be more powerful in school and for resume material, plus it does everything autocad can do. Plus, experience with solidworks makes going and using autocad rather easy, its not necessarily the other way around though.
Aerospace engineers use quite a bit of FEA/FEM analysis. I think he'd benefit more from a 3d program that can use these tools.
A student license is 139.99 with the cosmos analysis addins
SolidWorks at Academic Superstore