Matching jig for aligning rear and centre fuselage

It is evident that the top rail serves as the top reference for the fore-aft alignment of rear and centre fuselage. This is because of it structural function, and the proliferation of 4mm holes which cannot really be altered. It was found that the top strengthening channel hole alignment was also fully consistent with the reference established by the top rail. Since the top strengthening channel must be riveted into the rear fuselage first, due to the line of rivet holes along its top surface, it is essential that this can be positioned correctly. An aid to this is a jig made from 0.4mm positioning jig that imposes the correct alignment, without having to constantly positioning the side skins in place, which exposes the latter to mishap.