I haven’t done much over the last couple of weeks. I was out of town for work for a while and I’m still waiting on 20 or so individual replacement parts from TAF. While I wait, I’ve been mostly doing busy work.
I rearranged the center and rear fuselage to correctly line everything up for their eventual attachment. I’ve also started calculating wire runs for everything to start building wire harnesses. I’ve also been priming and painting parts before it’s too cold to do that.
One section I’ve built is the surfboard extension in the baggage compartment. Like the rest of the interior, I painted the sides with a dark grey epoxy and the floor with truck bed lining for durability.
Hopefully I get those missing parts soon so I can keep building the fuselage.
This week I prepped the center fuselage for riveting the underside. I built up the fuselage jigs, which are different than previous Sling versions. The way to tell you have them in correctly is by counting the holes in each cross jig. One hole is in the front, six holes is in the back. I then installed as many cross supports and stringers as I could to prevent any twisting or torsion when I tipped it over.
Safety Bulletin 14 requires different stainless steel rivets instead of the standard aluminum rivets. They’re quite different and appear much more robust than the aluminum ones.
I prepped the rivets by cleaning with acetone, then drying with a heat gun. Instead of 2 part fuel tank sealant, I used Eck corrosion sealant, as allowed by the bulletin. I did this because it came in a smaller quantity, so there wasn’t too much wasted. I’ll wait a few days for the sealant to cure, then I’ll clean the excess with a toothpick. I’ll then put it back right side up. I had 3 extra rivets, so I used them for my elevator control stop bracket.
Next, I’ll disassemble the temporarily installed supports and start planning my electrical runs.
I created a avionics planning page here. I’ll keep that page updated as I get further along in this build. It’s very top-level right now but it will get more detailed as I go.
I’ve been doing more prep, priming, and painting while I wait for missing and replacement parts. The center fuselage is ready to flip on its side so I can rivet underneath once the safety bulletin 14 rivets arrive. TAF revised the bulletin to include adding corrosion protection to prevent galvanic corrosion with the stainless steel rivets. The side skins are on temporarily to prevent torsion while it’s tipped over. I measured cross points to check for straightness, and it’s perfect.
Adding to the growing list of errors. The aileron control stops depicted in the instructions are backwards. They are correct in the maintenance manual, which is how I caught the error. I passed to TAF, so hopefully it gets updated in future instructions.
I also discovered that I have a Sling 4 firewall, instead of a TSI firewall. The holes are different so I am working that out with TAF. I think I might be able to get a TSI template and add the missing holes. That would be easier than shipping a new firewall from Africa. This is why I build up parts before I’m ready to install.
I’m continuing to build up the center fuselage using my process previously described. I’m not permanently attaching most of the parts, just making sure I have everything. My goal is to have everything painted before the winter hits so I don’t have to paint in the -10 degree garage again. I’ll work on wiring and electrical when it gets cold.
I discovered I’m missing some parts for the back seat and have duplicates of other parts. So I’m working with TAF to get that sorted out. My longerons are delayed due to the hurricane, so still several weeks out for those.
One minor modification I’m working out is making most of the internal panels and covers removable. That would help with any future maintenance, repairs, or upgrades. As far as I can tell, it would mostly just require replacing a couple of rivets for rivet nuts and screws.
My minimalist interior plan is coming out nice. The floors are painted with a truck bed liner that’s super tough. The side panels are gray epoxy paint.
Soon I will need to flip it over on its side to rivet underneath. I don’t want any weird forces, so I will cleco the skin in place to hold everything together. The side skins won’t go on for a while so I’ll store those after I get the bottom done. I’m waiting for the new stainless steel rivets associated with safety bulletin 14.
I also built a version 2 panel after talking with the Dynon folks. I’ll also build a panel page with planned specs and boxes.
Next is to keep building up subassemblies for fitting and painting.
I’ve been continuing my process of building the center fuselage. To try on cut down on build order errors, I first fit pieces and come up with a build order, then prep and paint, then finally assemble. The instructions are much more difficult to follow than the previous sub kits. The fuselage jigs are different than previous Slings, and there’s no instructions how to install them. I asked TAF for help and they sent some good drawings.
I have a few parts where the holes don’t line up. I worked with TAF and the issue was when the thick aluminum brackets were bent, it wasn’t a smooth bend. So I sanded the edges down to make it lay flat and it lined up much better.
TAF released a couple of service bulletins. Number 14 applies to me,and luckily I haven’t riveted the main spar on quite yet. I’m going to hold off until I get replacement stainless steel rivets so I can comply with that bulletin.
I’m planning on another non-standard thing for my Sling. I’m going to try to paint the interior instead of the normal fabric interior. I’ve seen it in a lot of Zeniths and can be nice if done right. The interior of the Pipers I’ve been flying get pretty beat up with these New York winters. So I painted my floors with truck bed liner on top of primer coats. It’s super tough and should handle snow boots easily. Thicker insulation layers and the huge heater I’m installing should make up for the lack of fabric. If it turns out bad or it’s too cold, I can always install the normal interior later.
Next is to start working on the center console, including the throttle quadrant. I’ve started piecing everything together then I’ll prime and paint.
I put aside the rear fuselage for now until I get the replacement longerons. Estimated delivery is in 6-8 weeks so it’ll be a while.
In the meantime, I’ve been working on the center fuselage. One thing to note is the kit comes with autopilot brackets for the Garmin servos. Since I’m using Dynon, I had to do some research. Fortunately, the mounting holes and positions are the exact same for both brands, so I can use those brackets for my servos. I riveted the rear section and began working on fitting the parts forward of that. I printed out Craig Maiman’s order of build for his hints and discoveries.
I also have been working on positioning of all of my avionics, antennas, etc. I built a wiring map to help out with that. I need to start working on planning the panel out and how everything connects to everything else. Dynon uses what is basically a power and data server that everything connects to, so it’s not impossibly complicated.
Next is to continue working on panel planning and building up the center fuselage.
I’ve been slowly making progress on the rear fuselage. I riveted the floor longerons and fitted the rear skins, not to forget the small skin at the very back.
I’m planning on installing a Rami AV17 comm antenna on the bottom, which isn’t standard. I’m putting it just aft of Rib 3, same as the top antenna. I made a bracket to mount it to and will run coax to that spot.
I’m still waiting on replacement longerons so I paused on the rear and moved to the center fuselage.
As I previously said, the fuselage instructions aren’t as detailed as the other sub-kits. Because of this, I’ve been building up the next few steps to figure out build order and anything missing.
I’m going to work on building a panel planning page based on my research. I’ll link that once it’s built.
Next is to continue working on the center fuselage while I wait for my longerons.