Category: Mid Fuselage

So I haven’t been posting a lot of updates recently as the end of summer ends up being a very busy time of year. Sorry about that. Progress is sorta being made and I’m doing a lot of jumping around between sections.

Currently I have mostly completed chapter 27 (Firewall) and working on section 28. I have also finished and tested both fuel tanks and now have them mounted on the wings (more in a moment). I’m getting quite space limited in my garage and trying to get the wings to a place where I can move them into longer term storage so I have a little bit more room to work. Hopefully I can line up some help in the next few weeks as well as a U-haul to make this happen.

Because I’m bouncing between sections and getting to loose ends, things sometimes get overlooked. Like when I dimpled the top of the gap fairing for the right wing, but forgot to dimple or countersink the 6 holes for the AN426AD4-8 rivets, and didn’t realize till I have riveted all the other rivets to the wing. Nothing to do but drill out ALL of those rivets, fix my problem and re-rivet everything back together.

Since I needed access to the top of the wing to drill those rivets out and both wings were in the cradle, I needed to enlist help to move the wings (one at a time) to a table to get access. Since I had access, I also decided it was time to mount the fuel-tanks to the wings. After starting to mount the first tank, I realized I didn’t countersink the holes deep enough on the spar. More clean-up work to ensure everything sat flush. It’s all little stuff, but it does take time.

Currently I still need to prime and dimple the bottom skin for the right wing, then I’m ready for both wings to go to storage as I’m not going to rivet the bottom skins on till I’m in a hangar and ready to mount the wings.

Last night my wife was able to assist me in getting more riveting done on the Mid Fuse bottom skins. Things were going great but at one point I got a weird feeling something wasn’t right. As we kept riveting, it finally hit me and I stopped riveting. One of the ribs seemed different and when I went back to look, I realized it was. Somehow I didn’t dimple one of the ribs and I was missing dimples on a few holes on the adjacent rib.

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Not sure how the heck that happened, but it is what it is. As I’m looking at it and trying to decide just how big this F**k up is, I slowly told myself to own my problems and fix it. Plenty of people today don’t want to talk about or embrace the mistakes they make. Social media posts celebrate the best moments, blah blah blah. Nope, that’s not me. I’m the guy that will crack a joke at my own expense and has no problem pointing out all the mistakes I make along the way. Not only do I point out my mistakes, I also do my best to fix them. Sorry, got on my “soapbox” for a moment.

With all of that said, I resigned myself to drilling out dozens of rivets so I can get a squeezer into the space between the skin and the rib so I can dimple the ribs I missed earlier. I ended drilling out a significant number of rivets to allow me to get my squeezer access to those ribs. Emotionally painful, but not a huge deal. Dimple the ribs, then bribe my lovely wife to re-rivet the skins back on. Overall, very happy with the results.

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Sorry, no time-lapse of this work as it was just nothing but riveting.

Now that I’m basically done with the wings, I can go back to working on the fuse. Section 26 – Mid Fuse Ribs and Bottom Skins will be creating the back half of the fuselage floor. As this will take up some significant space, I wanted to make sure I finished up the left over little stuff on the wings.

Before I even started, I read through the chapter to ensure I understood the sequencing. I quickly realized that I have to do a few steps, prime a few parts, rivet those parts together, then do the next few steps. This repeats throughout the chapter vs most other sections where I can prime and rivet everything at the end. Lots of little primer sessions in my future!

First few steps, build the Inner and Outer seat rib subassemblies. Nothing new with these parts. Only thing I should have done was to fabricate and include the flap motor mount parts when I primed the subassemblies.

Next, I start pulling the parts for the rear seat ribs and fabricating the seat belt brackets for them. Before I cleco these ribs to the bulkhead, I need to rivet the previous brackets to together. TIP: Make sure you flute the outer most ribs to match the bottom skin. (F-1015L/R and F-1018L/R). These are really the only ribs that need to be fluted, and as others have found it’s quite difficult to flute them once they are riveted together.

Again, nothing hard, just cleco, match drill, deburr, prime, and reassemble. About now, things are starting to get big so I ended up getting one of those “cheap” work platforms from the big box stores. Another option would be to stack some 2/4’s on the ground as a platform as the bottom skin needs to hang down past the forward bulkhead a bit.

Only other “gotcha” or oops I had was that I didn’t check the alignment of the F-1018R rib with the fuselage bulkhead assembly and allowed the rib to be trapped inside the flange of the bulkhead assembly. It should have been on the outside of the bulkhead and I had already started to rivet things together. Not a major problem, but I’m not a fan of double work. Drilled out enough rivets to allow me to move the parts into the correct position. From there, all is great and I’m able to build on :).

Lastly I start to cleco the skins onto the ribs and bulkheads. This was really cool to see and starts to make me worried about space issues in my garage. For now I’m rolling with the punches, but things may get interesting in the next few sections. With such a large part, I decide that I’m going to mark every hole I drill to make sure I don’t miss anything. Makes match drilling go a little slower, but I’m ok with that.

UPDATE: 4/7/2020 – One thing not fully covered in the plans is where to put the MFG heads vs the Shop heads in this section. Only when I went to install the rear seat floor pans did I realize there may be a recommended method. Where possible, put the round MFG head on the passenger visible side. It not only looks better, but also makes it easier to install the floor later on.

NOTE: While not called out in the plans, I would HIGHLY recommend that you dimple the F-1015B and F-1015A #40 holes now to allow the side skins to sit flush once they are dimpled. While it can be done later, it’s a pain in the rump. See Plans page 29-15 and 29-17 for rivet callouts.

Finishing up the Mid Fuselage Bulkheads, I continue by locating all the parts for the next bulkheads. I clean up and deburr all the parts on the ScotchBright wheel. Next I start the process of assembling and match drilling all of the holes called out in the plans.

With the improving weather, I was able to finish preparing the final parts for chapter 25 and get them primed without too much fuss. Once the primer has had time to cure, I’m able to begin the final assembly of the last two bulkheads.

Nothing too difficult on the Rear Spar Bulkhead. Just about all of the rivets are easy enough to set (only a few of the rivets on the gussets were slightly difficult to access). The only item that gave me pause was the nutplate holes in the F-1005A spar. Plans had me drill #40 and #19 those holes, but wanted to verify I shouldn’t countersink. Took a few mins of going through the plans to verify – leave them alone for now.

With that done, I move onto the Fuselage Bulkhead assembly. Very straightforward and easy to rivet. (I probably could have used the squeezer, but was already rocking it with the rivet gun at this point.)

With these bulkheads done, I putting them aside and backtracking to the last few items on the wings. Need to finish up the ailerons, flaps, tanks, and mount the pitot mast. Worried if I don’t do these items now, then they will be on the back burner for a long time as space will become an issue. LOTS to do, just need to buckle down while the weather is nice!

Continuing on with Section 25, I begin to work on the aft center section bulkhead. This is mostly a repeat of the forward center section.

I begin by collecting all the parts for this assembly, then final drilling as appropriate with my reamer. Not much to comment on and very few surprises as I began the process. Once completed, I disassemble and deburr. The weather has been nice the last few days and I was able to get all the parts primed without too much trouble.

After waiting 24 hours for the primer to cure, I begin final assembly of the forward center section. Install the blots per plans. I elected to put the rivets for the seat stiffeners in with the mfg head on the spar as I really didn’t want to use my offset rivet set. For the other areas where I could get a straight rivet set in, I put the mfg head on the primed parts. Honestly do whatever makes the most sense for you.

With the fwd section done, I begin to work on the aft section. Basically another repeat of the fwd section, just make sure you don’t rivet in those areas called out in the plans. Every now and then I would put a smiley into a few of the universal head rivets. No big deal, but I would drill the rivet out and replace. When you replace the rivet twice, that is a good clue to take a break and come back in a bit.

With both the fwd and aft center sections completed, I stored them inside temporarily to give me a little more space. I’ll probably finish off this chapter then go back and look at finishing up my tanks, flaps and ailerons just so I can get those parts off my shelves and attached to the wing stand.

With the Fuse delivered I wanted a break from working on the wings. Flipping to chapter 25, I start to work on the fuselage!

Starting off I have to fabricate some stiffener brackets out of angle aluminum. Looking at the stock sent in the kit it I attempt to figure out what length of angle to cut. Since I ordered an extra 6 foot section “just in case” I go ahead and use one of the 3 foot sections for these parts as it looks like they include extra length anyway.

Once that’s done, I make the appropriate marks, match drill the stiffeners, then jump into making the seat brackets. Lots of final drilling of parts as this is a pretty beefy structure. I may have overdone it a bit by taking parts off after drilling them to deburr, only to have to re-install them again to drill something else. Nothing wasted by my time, so it’s fine.

Looks like the more recent kits from Vans already have the appropriate cutouts on the spar (25-3: Steps 1-3), so that was nice. Then it was on to prepping the landing gear supports for attaching to the spar. I had to deburr and fiddle with the drill busing called out in step 4 to allow my drill bit to sit nicely in it, but that wasn’t too bad. Used plenty of BoeLube to keep the drill bit cool as I drilled the larger holes.

Once done (off camera) I made sure everything was labeled and then disassembled and deburred so I could prime.