Looking at a simple vertical shear moment diagram for a wing fuselage arrangement like the KR(treating the spar as a beam) with a questionable but perhaps not unrealistic assumption that the vertical load on the two longerons is equal (this assumes the weight of the plane is centered within the fuselage including the pilot or the fuselage structure equalizes the loads) and the wing loading is symetrical, the vertical shear force on the spar inside the fuselage is zero and the bending moment is constant and at its maximum across the entire width of the fuselage.
The vertical shear force is zero because of the assumption that each wing provides half the lift which is half the weight of the plane X G factor and that load is transferred to the fuselage structure at the longeron. ++++++++++++++++++++++++++++ Wesley I confess to being grossly uninformed on structural analysis and maybe at the dangerous stage of knowing only a little. I am very interested in the subject and thus read all I can and seek every opportunity to induce a discussion. As such I found your post stimulating - I made sketches as I read your post and what you say makes sense. I visualize the inverted aircraft with sandbags all over the wing - the pile getting biggest 3/4 the way out on each wing - and I am still struggling to see that the largest load is not in the centre (where left wing loads meet right wing loads) Maybe I should not see the loads opposing the weight of the fuselage as acting in the centre, but rather where the twain meet. Take care Steve J
