"Finishing the Wing Assembly"

Building the Wing Fairing

In order to finish the main construction phase of the wing, I had to get the wing mounts done, build the wing fairing and the belly pan. I used 1/4 x 20 nylon wing bolts and tapped them into 3/4" of birch plywood in the fuse.
With the wing mounted up straight and tight, I then proceeded to start building the wing fairing, which is of built-up construction on the outside of the fuse. The latest revision of the Bates plans now has this fairing built right into the actual fuse formers and you sheet out over them. But for mine, I used a triangular piece of 1/16" aircraft ply, which has small formers added on top of it, connecting it to the sides of the fuse. This acts as the fairing base.

After adding some tri-stock support, I then added the top piece of 1/16" ply to close up the front section of the fairing. Next I built the trailing section out of balsa, attempting to get the proper shape and curve that would allow me to blend it back into the tail moment. I then used 1/16" balsa sheeting to plank over the entire fairing construction.

With the fairing planked, it was a process of sanding, puttying, standing back and squinting, looking at three-views and photos, sanding some more, puttying some more, and so on until it was "just right." The goal being a fairing that had the proper shape and scale, but also blended and feathering smoothly into the fuse.
This whole process was a real pain, but I'm pretty satisfied with the end results and confident that it is good and strong.

The Belly Pan

Now onto the belly pan/bomb fairing. This was done by starting out with some 1/2" balsa blocks that I placed down onto the wing just in front of the wheel wells. These would support the belly pan and would later be shaped to follow the contour of the fuse where it wraps around the leading edge of the wing.

Next I used a couple planks of 1/2" balsa sheeting, gluing them together then cutting out a rough plug of the belly pan area. I then marked it up with scale lines to show me what the basic contour would be and where the cutouts needed to go. I then cut it to final shape and size, and proceeded to sand it down to the final shape that would blend it into the wing bottom.

With the belly pan cut to final shape, I glued it into position on the underside of the wing. I then marked the contour of the front fuse onto the new structure and pulled the wing off. Now I was able to sand the balsa blocks under the belly pan down until they followed the shape of the fuselage around the leading edge and blended them out onto the wing. The last little "teardrop" shape at the trailing end of the belly pan was then cut off. I'll end up gluing that small section onto the center flap later.