Next on the list was building the firewall (Section 27). After pulling the firewall out of it’s protective shell and locating all the needed parts, I was able to start clecoing everything in place. I found there was some finishing work that needed to be done to get all the firewall braces to fit together properly. Nothing major, but just a little different than most of the other areas so far. Maybe that was to make sure that you had a pretty tight fit between components?
One thing I’ll note that is ever called out in the plans. The stainless steel firewall is SHARP. I really tried to be careful around it but did end up with a few fairly deep cuts on my hands. Worst papercut ever!
Once all the braces were final drilled, I moved onto the tunnel. Nothing really difficult here either beyond measuring where to drill for the SCAT tube support. Cleco the remaining parts together, final drill then deburr everything and prime.
With all the parts primed, it was time to deburr the firewall itself and dimple. A few things I’ll go ahead and call out.
- As called out on Page 27-5, two nutplates are installed on the engine side of the firewall. This isn’t mentioned in the steps but dimple correctly for these nutplates.
- I went ahead and dimpled ALL the holes on the firewall as I was unsure if I should or not. Were I to do this again, I would not dimple the holes under the F1001-C (bottom of the firewall) as a squeezer could get there later. Can’t comment on Upper Fuse ribs yet.
Riveting the braces onto the firewall skin was straightforward. Just don’t rivet the area where the triangle brace goes or you will need to drill that out later. I ended up backriveting most of this with only a few minor issues. I supported the firewall on scraps of plywood so I didn’t bend any of the flanges.
The only other “mistake” I made was when I was riveting the WD-1004 brace to the tunnel skin. I read the note, but still put the rivets in backwards. Drilled them out and put them in correctly just in case. Honestly it was easier to rivet following the directions (shop head on the WD-1004 side)
At this point my mid-fuse bottom skin is still not riveted together, just waiting to get someone over to help me set these rivets. Maybe I could back-rivet these on the bench, but getting a helping hand seems like a better idea.