F-1296A&B Tailcone Fairings Match Drilled

A very short work session yielded very good progress on the F-1296A&B tailcone fairings. After the initial trial fitting done during the last work session the plans instruct the builder to install the eight F-1294C tabs. Installing the eight tabs is a multi-step process beginning with temporarily clamping the F-1294C tabs onto the outside of the F-1296B lower tailcone fairing. Once the tab is clamped in position, the two rivet holes in the F-1296C tabs are matched drilled into the F-1296B lower tailcone fairing. There are no set locations given for positioning the tabs … other than placing two tabs adjacent to each of the mating surfaces. However, that said, there is a notch on each side of the tab and the notches need to be placed centered over the edge of the fiberglass. I chose to position the tabs 1/2" in from the edges and sides except for the two tabs on the top on either side of the slot … there I chose 1/8" in from the edges.

Using the two lower holes in the F-1296C tabs to match drill the F-1296B lower tailcone fairing with a #40 drill.

Finished match drilling the bottom holes of all eight F-1296C tabs into the F-1296B lower tailcone fairing. Note how the notches in each of the tabs are centered on the edge of the fiberglass.

Next the F-1296A upper tailcone fairing is set in place with the tabs still on the outside of the F-1296B lower tailcone fairing. The upper fairing is clamped to some of the tabs and the center hole in each tab is used to match drill the F-1296A upper tailcone fairing.

With the eight F-1294C tabs still on the outside of the lower tailcone fairing, the F-1296A upper tailcone fairing is clamped in position for drilling.

The center hole in the F-1294C tab is used to match drill the F-1296A upper tailcone fairing with a #40 drill . These holes  will be enlarged later and become holes for the mounting screws.

After all eight of the center holes in the F-1294C tabs are match drilled into the F-1296A upper tailcone fairing, the tabs are removed and the holes cleaned up. The tabs are installed again ... but this time they are secured with Clecos to the inside of the  F-1296B lower tailcone fairing.

All the holes have been cleaned up and the F-1294C tabs moved to the inside of the F-1296B lower tailcone fairing so the F-1296A upper tailcone fairing can be secured with Clecos. Note the tabs are now inside the fairing pieces.

This is where I stopped for the evening. Next the center holes just drilled are to be drilled out to #27 with a drill bit that has been purposely dulled by drilling into concrete. I have already countersunk the nutplate holes on the tabs prior to priming, so after the nutplates are installed the tabs can be riveted in place after the rivet holes in the F-1296B lower tailcone fairing have been countersunk ... something to look forward to during the next work session.