Steve, wouldn't the carbon part be much stiffer with the core? That is what I was thinking. The tall 7 has been seen in pieces (5 incidents). It is innocent until proven guilty (of course), but it seems to fail in bending along a line extending from the upper pivot bearing aft to the TE. Roughly. Some dynamic load, stimulation, resonance, flutter etc. Anyway, the whole line of curiosity was the possibility of a different, stiffer design. Although, the aluminum design is a torsional component (the aluminum one), it only has end caps, spar and TE connected with ribs for stiffening. It seems the shear loads would applied to a stiffer "skin" would render the entire rudder stiffer in torsion. When I clamped the tall rudder (.016 skin) to the bench with the pivot pins mounted to a stiff steel beam, it seemed like there was some low torque dead-band until the angular deflection was enough to stiffen the skins. Minor buckling?? Is that expected?
How are carbon parts fastened together, could two skins attach to a trapezoidal beam (spar) and then to themselves (TE) with adhesive? Or does adhesive have inadequate shear strength?