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Wednesday, 22 April 2026
Flying!
First Maintenance
Flying requires maintenance. And that's where I am... well have been, because its almost done.
UL Power requires the following at 15 hours
- Change oil and filter
- Check valve lash
- Torque cylinder heads
- Clean course (pre filters), change fine filter.
- And check everything else.
Thursday, 16 April 2026
Flying!
It's kinda surreal... after over 9 years of building I now have an airplane. That was always the goal... but when you consider the project 1000 little projects, you lose sight of that.
Not that I don't have bugs to work out. But honestly there are few.
The header tank gave me some issues... now 7 hours of flying in with the changes and no issues. That is a good feeling.
Aileron cables were either not tight enough or stretched. Regardless, they are now back where they should be.
Airmate maps installed on my panel. That is very cool.
No leaks... that is nice.
Tweaking my forward cylinder cooling. The fronts are a bit cold, the middles are a bit hot, and the aft are just right.
Engine runs great... just burns a lot of fuel. 10 gph is normal.
Flight testing continues. Next is to configure the AOA. Needs some help with that one (2nd pair of hands).
Some pics from a friend on the ground last week.
7 hours and counting. 18 to go.
Minor prop issues... the controller would go into current limit when switching modes in the course direction (from TAKEOFF to CLIMB, or CLIMB to CRUISE). Checked everything, and all I could find was one brush that was not wearing evenly. Changed that, problem continued.
Airmaster had me increase the current limit from 4A to 5.5A. That solved it, but they are sending me a new motor that is stronger and has higher gearing.
Need to do climb test, but that will not be a problem.
Lots of comments about the sound... does not sound 'normal', like a lycoming. And the 4 blade prop has a distinct sound.
Sunday, 5 April 2026
Fuel system changes, and second test flight.
It's been 9 days since the first flight. Been working to understand the header tank issue so I can fix it.
First was to essentially redo the fuel flow test to understand if the vents are working properly and fuel / air can move where they need to move.
For the first flight the header tank venting system went like so:
- From the header tank, two vent lines come out of the top and run horizontally towards each wing.
- Make a 90 and head aft and go up the door frame. From there they go along the top of the door to the wing hinge just forward of the aft spar.
- Then they make 180 and go forward and are attached to the root rib. They transition around the forward spar and then into a conduit along the leading edge of the wing.
- They exit the leading edge at the tip and are T'ed into the vents from the main and aux tanks.
- Then into a Andair checkvalve, then to the JD airparts vent under the wing.
- The fuel flow with the original and new vent configuration is the same.
- The right wing was transferring fuel averaging 30% slower than the left.
- I separated the vents at every point possible and redid the test. Was always within a couple percent of each other.
- Folded the wings (again). Took out the finger strainers. Strainers were clean, but there was construction debris (what my friend Geoff calls 'sworf'). Cleaned. Tested again, no change.
- Focused on the areas between the wing root and fuel selector. Drained the lines, took every fitting apart and checked. Found some shitty pipe ends that needed some filing.
- Removed the fuel valve. Tested from the wing to the input of the fuel valve. Both sides where identical.
- Did a flow test on the fuel selector. Same on both sides.
- The lines from the wing to the fuel selector are 3/8". The output of the fuel selector to the header tank was also 3/8". No bueno. I had the right fittings to change that to 1/2". Header tank removed. Drilled and retapped the tank (luckily the boss was HUGE). New 1/2" fitting on the header tank.
- Reassembled EVERYTHING and tested. Now the flow is within 5% of each other. On BOTH the fuel flow is considerably faster.



