Aircraft Rigid Lines
Solid lines are strong and durable but can be subjected to damage during installation, removal and in some cases these lines have failed from resonant harmonics. These types of lines look just like the metallic brake lines going to the rear wheels of your car. This is also the most likely place you will use them in your gyroplane kit. Solid lines in aviation can be found carrying almost any type of fluid, fuel, oil, water, and hydraulic fluid.
When installing these lines pay particular attention to clearances with the surrounding structure and other lines. Check for possible chaffing and proper support along the run of the line. After installing and tightening the fittings apply torque seal to the B-nut to facilitate future inspection.
See AC43.13-1 for more information on rigid lines. You will only have a couple of these lines if any on your gyroplane. Go to Aircraft Tubing to finish up this section.