Butt ribs are a pain in the…

Today was butt ribs day. It is suggested in the manual that once you attach the wings, you take that opportunity to attach the butt ribs to the fuselage. These ribs basically trim out the transition from the wing to the fuselage. They aren’t structural so it is really just a matter of lining things up and putting them in place permanently.

The instructions were, “Install inboard slats and tape them in place. Open wing slightly, mark where butt ribs go, cut, drill, rivet. Done. Since it was supposed to be 100 degrees (in June?!) we got to work about 6:30am. That was fine for me because I’d already been up several hours. For the boys, there was some pain associated but they never uttered a complaint.

We rolled the airplane outside, then decided to take the rear stand off so the plane could roll on the newly installed tailwheel. It rolls really nicely, as in I can imagine myself taxing this thing and I’m excited. The locking pin isn’t unlocking as I’d like but I’ll see if I can tweak that. We unfolded the wings and then rolled the plane under a large willow oak tree in the yard.

Plane outside under a shade tree, ready to be worked on
Plane outside under a shade tree, ready to be worked on

The boys took all the previously removed tail feathers and swapped them for the slats that had been tucked away since coming back from Robby’s. Once we figured out which slats were inboard and which were outboard, we went outside to tape them to the wings.

As soon as I got to the wing, my stupidity was obvious. I’d read the instructions to tape the slats to the wings as in, hold them in place, put some tape on them, install the butt ribs. When what it meant was, fully install the slats on their dual bearing, hard to install, needs a hydraulic press to press the bolts in, hardware. The pressure was on to get the slats installed before it got too hot. That way we could get the butt ribs installed, then remove the wings and carry the entire project back inside where it would stay for the next month or two.

The slats are specific to where they go, so there is a left and a right, and an inboard and an outboard. We set about fitting out all the hardware and then installed the right slat. The slats were already helpfully labeled by somebody left and right and we’d already figured out the outboard and inboard. With the first slat installed, I tightened down the hardware, fully seating the bearings in place. Then I tried to fold the slat into its stowed position. Nope. What?! I looked at the backside of the slat to see what was hitting. What was labeled as the right slat was actually, and now obviously, the left. I looked down at the one labeled left and saw it only fit the right side. Argh! They had been mislabeled!

The hardware was next to impossible to get in place and now we had to remove it. What ensued was a break for the boys while I went as far as driving to the machine shop to get ideas. Fire, ice, welding, all the normal things were suggested. I had to keep telling them that this wasn’t a tractor, we couldn’t do stuff like that. Eventually we circled around to slide hammers (I own one) and using vice grips to grab the head of the bolt and using the slide hammer to grab the vice grips and pull the whole thing out. I drove back home, setup as suggested, and with Spork’s help and some banging, we removed the offending bolt so we could get the hardware all back in one complete set (they are matched to each side). We ruined the AN4 20A bolt in the process but that was a small price to pay.

With the slat now removed, and the temperature around 95 degrees, we folded the wings and rolled the whole project back inside, defeated, to await another day.

So what do you do with two boys on a 100 degree day when they are supposed to be doing airplane stuff?

Boys washing the Citabria
Boys washing the Citabria

You take them to the airport to wash an airplane, that’s what. We pulled the Citabria out of the hanger and wheeled it over to a patch of grass where we could kick off our shoes and have some fun. It isn’t a big airplane and it doesn’t take that long to clean. Plus it was covered in bugs from the last few flights that I had taken (one with Cody on his first flight!) so I had some ownership of its condition. There was a bit of spraying each other and general horseplay. The plane looked shiny new when we got done in about 30 minutes. Everyone was pleasantly damp and we hopped back in the truck to take Cody to meet his dad for a trip they have this week.

Wednesday will be a no airplane day and then Spork and I will be back on it on Thursday. We have a lot to do, ELT installation including mounting the antennae, making a battery box from scratch and then installing it. Installing the battery itself and it’s wiring, getting the slats mounted, correctly this time, installing the fuel lines, and finishing painting the spoilers. The idea is to have the airplane ready to install the butt ribs when Cody gets back, then start on the fabric covering. That way we’ll hopefully roll through the fabric covering over the next several weeks, getting the plane basically covered. Once that is done, it is onto painting. Somewhere in that process the avionics will show up, meaning it is time to install the instrument panel and do all the associated wiring.

I’ve also ordered the shocks and engine, meaning once the fuselage comes off the stands after covering and painting, it will go onto the tires and stay there. A covered, painted, roll around airplane is deceptively close to being a ready to fly airplane.

With both boys helping, things are moving quickly and I hope covering goes well. We could be painting in a few weeks at this pace.

When I first looked at this project, I was daunted by the amount of work needed to complete an airplane. Now I’m looking at the number of projects left, all of which are significant, and thinking yeah, we’ll be done ahead of schedule. Sun N Fun 2019 is April 2-7th next year and our goal is to be there with this airplane. That is completed and the 40 hours Phase 1 time period flown off. Since I normally fly about 150-200 hours per year, that is a large amount of time to fly. We’ll see.


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