Construct wing mid-span support jigs and remove wing-tip jigs

I have chosen to continue to use the wing root jigs while completing the wingtip structures, in order to preserve needed access and clearance for the adjustment and closure of the flaps and ailerons. Supports need to be constructed to support the wing in such a way as to permit removal of the wing-tip jigs while ensuring enough access to the wingtip to enable rivetting. These supports are wooden box structures located just past rib 9, butted against the aileron hinge bracket. These supports are designed to support the wing in exactly the same manner as the original wingtip jig, by following both the vertical location as well as washout angle of the bottom wing surface at this rib location, determined with the help of the laser level. By design, locating this support at one edge of the 97cm wide workbench ensures the wing tip rivet holes overhang the other edge sufficiently for full rivet-gun access.