Dense cargo positioning
Suppose you have some very dense cargo to transport on a freighter plane. I mean really dense, think gold, tungsteen, marble blocks, something with which you will max out on weight way before you max out on volume. Where should you place it, in the belly or on the main deck? Does it have any implications on the plane behavior in-flight? I'm not talking about CG, it's obvious you need to mind that. I'm talking about the vertical component.