Pitot/static hooked up
Now that the engine runs, it’s time to knock out the rest of the little details. The most major detail was finishing the hook ups for the pitot and static lines. These air low pressure air lines that run to the instruments for calculating speed, altitude, and rate of ascent/descent. I ran most of the tubing a while back, but discovered that the Trutrak autopilot and AFS EFIS have the ports too close together to use T fittings. I ordered some straight fittings a while back, but have been too busy to install them. There’s not much room behind the panel, but I eventually got everything hooked up and the autopilot re-installed.
I used a trick I read about for testing the system. I bought a few feet of surgical tubing from Lowes and stretched that over the pitot tube. I pinched the end closed and slowly rolled up the tube to increase the pressure. Sure enough, the airspeed indicator and EFIS both registered the same speed. I held it for a while to make sure there were no leaks. The static system was a little trickier. I had to hold the surgical tubing up to the static system with it already rolled up and then unroll it. I was able to get a few hundred feet of altitude on the EFIS, but I really need another set of hands to do it right.
Next I decided to knock off an “easy” task from the list, fixing the safety wire on the autopilot roll servo. It was a bit too loose. After 3 tries, 20 minutes, and a bit of swearing, I eventually got it looking better. I’m not a big fan of safety wire.
Since the autopilot was back in, I decided to test it out. I remember switching the roll servo wires months ago when I first tested it. Well, I somehow reversed things in my mind. I had to switch the wires again, and it started working correctly. Increasing the heading should make the stick tilt right. The pitch servo has been in and working correctly for a while.