Good day in the shop today. Time to start plumbing the wing for pitot, static and fuel lines. 50 feet each of blue and yellow nylon line and 20 feet of Earls's Auto-Flex fuel line:
I'm not ready to get the fuel tanks welded yet, but they are taking up a bunch of room on the bench, so I "dismantled" them for storage. Before putting the skins away, I decided to drill out the drain hole.
Step drill brings the hole up to 18mm diameter:
The tank drain fitting will be welded here and eventually will have the drain valve installed.
Before flipping the wing upright, I cleaned up the bench completely. It was getting quite untidy with all the bits, pieces and other tools. I laid down some green tape runners on the lower skins to help protect the skins where they will ride on the steel bench tubes.
Ron helped me flip the wing over and I was pleased to see the tape runners I put on the upper skin helped prevent most if not any scratches:
The nose skins are just wider than the bench when they lay flat, so I tagged the corners with a bit of yellow tape . It won't protect the corner, but it catches the eye when walking by.
Here is a better look at the pitot/static tube inside the nose skin now that the wing is upright. As mentioned before, I'll need to trim the length a bit to leave room for the the union connectors:
Here the connector unions in place on the end of the tubes. They point right at the spar web, bending the tubes into the lightening hole isn't practical.
A couple of holes in the spar web are necessary for routing the lines, but I like this better as it is another way to support the lines as they pass towards the rear channel:
Grommets protect the lines in the holes. I won't be connecting the probes until later as I work on wrapping the nose skin. Blue line is pitot (airspeed) and yellow line is static pressure (altimeter, VSI etc.):
The lines pass through the wing bay and out through the rear wing channel, again through grommets to protect the lines:
Not all leght of this line will end up in the airplane, but I'm not cutting anything I don't have to (less cuts means less potential leaks/failure points). For now it stays coiled up. Eventually it gets routed through the cabin, under the seats/floor and up to the instrument panel. I'll likely need more union/elbow connectors, but that's a ways off yet.
Next I worked on laying out where the fuel line leaves the left wing tank and travels though the inboard wing bay rib and eventually through the rear channel and out inside of the trailing edge to the fuselage.
The outlet fitting isn't welded yet, so for test fit I taped it in place:
The inboard tank rib (side of tank) sits inside the fuel bay of the wing once part of a completely assembled tank:
I lightly clamped the rib in place. The goal here is to approximate the location of the pass through hole in the wing rib foward/rear, not the distance laterally (left/right):
I marked the location of the pass through using a Sharpie through the centre of the fitting then drilled a pilot hole in the wing rib:
Using a the step drill, I enlarged the passthrough hole a little at a time until the finger strainer fitting from the tank could fit through. The aluminum plate is a piece of scrap I placed on the lower wing skin to protect it from scratches from the drill chuck:
I traced the size of the fuel outlet fitting centred on the passthrough hole, then enlarged it a bit more. This will give me a bit more room when I install the tank. The fittings and line just need to pass through here, they don't actually fasten to the rib.
Looking at the wing tank rib, facing inboard with the finger strainer in place:
Looking at the finger strainer, outboard towards the wing tank:
I can't do much more tank fit up until I get the fuel caps and fuel level sending units I ordered.
Looking back inside the wing, I needed to come up with a way to support and protect the pitot/static lines from rubbing on anything from vibration. The lightening hole flanges of the nearby wing rib face toward the lines, so clipping them to the surface of the rib won't work.
Using some scrap 025 aluminum that was already bent 90 degrees, I created some stand-off brackets
While the standoffs dried after priming, I remembered I needed to final torque the forward wing strut attachment bolts - so much easier with the wing upright!
Some 1/4 inch cable clips facing back to back get rivetted to the standoff then the standoff rivetted to the wing rib:
Nice and tidy and secure from vibration damage:
The standoffs are perfect, very pleased at how neat this arrangement is. Once the final fit of the lines are done at the pitot/static probes, I add a wire tie on the lines to prevent them line from sliding back and forth in the clips if needed:
Gentle bends supported well prevent the lines from kinking. There is plenty of room inside the trailing edge for a large radius bend in the lines as they exit the rear channel:
Cable clips avery 11 inches spaces out nicely along the face of the rear channel as the lines head inboard towards the fuselage:
Tied the nose skin up a bit with some twine which allows anyone walking around the bench when I'm not working on the wing to do so:
Good productive day. Waiting now on some plumbing fittings, fuel caps and fuel senders. I've got to drill and grommet the fuel line hole in the rear channel, then I can fir the trailing edge. While I wait for my orders to come in, I'll get the nose skin slotted for the slat pick-ups and wrap the nose skin.
More to come, thanks for following along.
New here? Try starting at:
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.