Step Bushings – The steps on the RV-10 are known to loosen over time, which could be caused by the bolt that holds the step to the step mount really doesn’t have anything substantial to work against when it is tightened. In addition, as the bolt gets tightened, it crushes the step tube and bracket, making the step oval instead of round. Therefore, TCW created a solid bushing that fits inside the step tube to give the bolts something to work against. With the bushing pressed inside the tube a real clamping force can be established between the step tube and the step bracket. The hole in the bushing is LARGER than the actual bolt so the bolt would easily pass through without any difficult alignment issues. The hole is 1/4″ and the bolt is an AN-3.
Fuel Fittings – Techniques vary for routing of the fuel lines through the tunnel area and out to the wing tanks. For example, the Van’s procedure has 3/8″ aluminum tubing in a series of bends that must be made with the tubing down in the tunnel. Afterwards, there is a stub of tubing sticking out of the side of the airplane until the wings are attached. Other techniques include opting for flexible lines from the fuel selector valve all the way to the fuel tanks or using AN type bulkhead fittings to pass through the tunnel and then through the fuselage. The problem with the bulkhead fittings is that the pre-punched holes are 1′ in diameter. A bulkhead fitting would fall through this size opening. TCW’s fuel fittings adapt to the AN bulkhead fittings to the pre-punched holes.