Pitot Mast Install

With the pitot mast powder coated, last night I finished up the pitot tube install. Since I’m using the Gretz mount, and the wings are going to be stored for a while, I’m going to keep the mast and pitot tube uninstalled until I mount the wings. At this point I’ll just get all the fittings attached to the pitot tube, and bend the aluminum tubes to clear the aileron push tube.

Having not bent any aluminum tubing before, nor flared tube ends, I had some experimenting to do. I had the tools, but hadn’t spent time learning to use them. EAA’s hints for homebuilders has a couple of great videos on this, if you can find them. I had some scrap 1/4 inch tubing to practice with. I used some scrap to make a template of the bends I needed, which allowed me to ensure I can route the pitot and AOA tubing around the elevator pushrod that would otherwise interfere with the tubes. I was also able to confirm that I will be able to pass the pitot tube through the mast, given the bends I was making.

Template for the planned bends

The only real problem was working with the two tubes (pitot and AOA). Bending the first one was easy, the second slightly harder due to interference from the other tube and the tube bending tool. Following a slightly different line, I worked around the issue.

Mast was able to pass over the bends no problem
Test fitting onto the wing. This will be fine

The next step was to trim the tubes to give plenty of clearance from the top skin. Tube cutter worked ok, but again some interference with the other tube created a small problem.

With the tubes trimmed it was time to install the sleeves and b-nut, then flare the ends of the tubes. Apart from the interference issue, this was an easy step.

Flared tube ends keep the sleeve in place and help create an air seal

Then I was able to answer a question that I had been contemplating, which was how to run the wiring between the pitot tube and the controller. There is a rib between the pitot tube location and the controller location. The connectors are bulky and I’d need to either cut them off and rewire after passing through the systems hole, or route them through the lightening holes in the rib. I found I could pop out the snap bushing and pass the connectors through the systems hole in the rib. This will allow me to use the systems hole for the wiring, as I can cut a slit in the bushing to pop it over the wires, then push into the systems hole.