ah, I should have known there would be a problem... of course, there's no battlescape in the baseview, so that's difficult... uh, I don't know.
there's also the problem that soldiers in the transport craft should only have access to the equipment that's loaded onto the craft, while the soldiers not assigned to a craft should have access only to equipment present in the base. so if you try to equip soldiers from the basescape, you have access to both groups, but each has a unique "pile" of equipment to access.
I guess it is not easy at all.
I would say that for sake of simplicity, perhaps you could include a button "equip soldiers" in the craft view (the one where you see the overview of what's on the craft, not the item list), which invokes a fake battlescape with the craft's contents - clicking on "OK" returns you to the craft view. what do you think?