I understand the aero requirements for CG, stability, etc, (rather, I understand that they are IMPORTANT, and I have much reading to do ). Concerning actual "nuts and bolts": when designing an airframe, how does one determine the wing location in the structure? I understand weight and balance thoroughly, but that's when I can put my hands on something and weigh it and know where it is placed along the arm. How do you deal with the "theoretical" weight of the aft fuselage, tail, wing, etc, when they are still on paper? Is the process as simple as finding similar components that DO exist and then take your best shot? Is it OK to adjust the wing position a few inches fore/aft as you actually build parts? Seems like a chicken/egg thing...