Created the flap substructure for both left and right wings. Image 1 shows the technique I used to assist in locating the proper height of the flap spar for installing the hinge fitting. I used string weighted at the trailing edge and restrained at the wing aft spar. Then the flap spar was centered between the strings and the hinge fitting located. Image 2 shows the right flap substructure riveted and hanging from the pivot fittings. Finally, image 3 shows both the left and right flap substructure riveted and hanging from the pivots. Next step will be to make the aileron hinge fittings and weldments. (need to order more .063 4130)