All 4 rear wing spars have been drilled using spar drilling jigs. Through the kind assistance of John Robert,his CNC data for the main and rear spars was used by Johnathon Pritchard to fabricate steel water-jet-cut drilling jigs for the spars that precisely place every rivet and attach bolt hole in the spar webs and spar caps. The combination of the jigs and the separate spar components (along with some judicious use of clamps and spacers) in a kind of sandwich permits you to drill all of the holes in the assembly with a high degree of accuracy; John Roberts reports an exact matching fit between his jig-drilled spars and his CNC-cut fittings. Even though I plan to use hand-fabricated fittings, I still see the use of spar jigs as a time-saver and better guarantor of accuracy. Once I am done drilling my spars, these drilling jigs will be available for other Midwest-area Skyotë builders to borrow and use; I will make them available at no cost to the borrower except for shipping and return.