[January 16, 2010]

I used a union fitting for the pitot line to make it easy for me to run the pitot lines in the wings. If I went with one long pitot run, I would of had to do all of the routing of the line with the wing on the airplane. I bought this fitting from Coast Pneumatics. The company SMC makes the fitting, and its part number is KQ2E07-00. I believe it was around $5.00. The complete line of SMC connectors is in this Catalog (Be aware this is about 50 MB large!).

I used some blue locktite on the fitting to keep it put. In order to make the sharp bend of the pitot line I heated the tube up with a heat gun to help with it bending and not kinking.

I secured the line right before the spar with an adel clamp before I routed it in the holes I made when I built the wings.

Here is a pic from inside the wings to show how the tube was routed.

Passing by the bellcrank I used another adel clamp.

To finish off the pitot line routing in the wings I used some wax lacing cord to secure it to the wing conduit. I didn't want these two items vibrating against each other.

One item that has been on my list for a LONG time is drilling and tapping the pitot tube for the screws that attach it to the pitot mount. The mount came with holes already in it -- I believe their diameter was about a #18 drill bit. I bought special screws for this task. Because there isn't a lot of "meat" in the pitot mount to tap, it was suggested I go with a 6-40 screws instead of the typical 6-32. The 6-40 will give me an extra one or two threads so theoretically it will be a little more secure. Another issue with this project was I couldn't drill too deep into the pitot tube because there were the wires and pressure tubes coming out of it. I could not nick either of them.

My process for installing these screws was to first mark on the pitot tube where the holes needed to be. I used a #18 drill bit for this, rotated a couple of times to make a mark on the pitot tube. Once the holes were marked. I drilled them to a #40 with a drill stop to keep me from drilling into the wires or tubes in the pitot. I then reassembled the pitot tube with the mount and countersunk the assembly for the 6-40 screw. Once that was done. I enlarged the #40 hole to a #33 and tapped the hole for a 6-40 screw. Turned out excellent.

If anyone would like some of the 6-40 screws, let me know. I needed to buy 50 of them to meet the minimum quantity order.



Last Modified: May 19, 2024