Yes, you can, by editing the MEinit.xml file. I modified the Su-33 to be able to carry Kh-29L A-G missiles. You then lock and launch them in the same way as the Su-25. I modified the loadouts so that I can add six Kh-29L missiles, six FAB-500 bombs in pairs of three on two pylons and four A-A missiles, its a heavy loadout but, very destructive. Just open the MEinit file with notepad, search for the Su-33, look for it's pylon configuration and add the compatible weapons you would like. I also added the Kh-65 nuclear cruise missile to the Su-33's loadout. I can post my MEinit.xml file for download if you would like to use it as an example.