CHAPTER 46 - Aft Structure

The first step to the aft structure was to trim and install the aft deck and bulkhead. Trimming the aft deck to fit around the stab mounts wasn't difficult, but I found my fly-cutter would not extend to make the desired holes. I ended up cutting them with a nibbler and then filing them smooth, a long job. The first photo shows how I have clamped the tail to keep it from twisting (2x4 clamped to a sawhorse, which also supports the tail) and shows the deck in place. At this point, none of the underlying structure has been fitted.

Next I jumped ahead and started on the baggage area, which served to stiffen up the baggage compartment bulkhead. You'll read about that in the next chapter. With the baggage area fairly firm, including the vertical rib that supports elevator bellcrank, I was able to install the upper stringers using sidegrips to make sure the bulkheads were plumb before drilling them. Then I could position the top support rib and fabricate its attachments. The second photo is of the rear attachment while the third photo is of the forward attachment, including the gusset. The next photo lets us peek under the gusset to see how the verticle rib attaches at the top of the bulkhead. Next we take a step back and see the overall arrangement of the top structure.

Now I returned my attention to the structure under the aft deck. Removing the deck, I began assembling the pieces. In the photo you can see the forward elevator stop, which is resting on the angle at that bulkhead. You can also see the clamps holding the angle at the next bulkhead, a shim was fabricated to sit on top of that between the longerons to act as a filler, much as the forward elevator stop functions as seen in the final photo. After all the structural pieces were fitted and the angles drilled to the longerons, the aft deck was reinstalled and then drilled to the new structure.