Today I made the vent lines for the fuel tanks. I installed the vent elbows in the sides of the fuselage and then began measuring the length for the tubes. 

Here you can see the AN818 fitting. Mirrored on the right side. This will attach to the fuel tank in the wings. 

Here is the inside of the fuse. The vent line snakes up and around then attaches to the floor vent. 

Here’s the left side. The tube bends around the stringer and the rudder cable, then bends around the perimeter. A lot of the bends had to be made by hand, and it’s quite tough. 

Here’s the complex bend around the cable. 

The pair of the vent lines will be installed and then I can begin installing the other cabin systems.