Brantel
Well Known Member
I seem to have a large static position error... I think that is what you static system guru's call it.
One possible theory is that I have my vinyl N numbers right in front of the static ports and that these are causing some sort of turbulence creating the error?
What says the guru's???
Here are some pics of the install and ports:
- I have the SafeAir static ports that are of the new design.
- They are mounted inside the fuse by the way of Pro-seal around the flange to the inside of the fuse skin.
- The ports extend from the side of the fuse .051 on the left and .053 on the right.
- The ports are within 1/2" horizontal and dead on the vertical position as specified on the plans.
- The SafeAir ports are round with square corners on the OD and the ID. There is no radius or chamfers on these ports. They look like an exact cylinder sticking out from the skin of the fuse with a hole in them.
- I used the SafeAir tube and fittings and the static ports are cross connected with a "T" in the exact middle between them. The static line is connected to this "T" and runs up to the D100.
- On takeoff and climb out I noticed that even though I am climbing, the altitude seems to stay pretty much at field elevation until I get to around 200ft then it starts to roll up normally. ( I think as the airspeed comes up, this is increasing my error and the error is canceling out the fact that I am climbing until the higher altitude overcomes the error)
- When flown beside an airplane that has been proven accurate, my altitude indicates almost 200ft low and the airspeed was also low by at least 20 knots. I did not get the exact numbers but mine was low on both. This was with me running around 2350rpm @ 3500ft.
- I popped a flap fuse while landing which may be because I was above flap speed at some point and did not know it since my ASI is reading low.
- I have performed a vacuum leak test on the static system where I applied 1000ft of elevation change for at least a minute and there were absolutely no leaks. I taped over one port and used a vacuum tool to suck it down.
- I made a manometer and downloaded the chart from the "Fly EZ" site and performed an ASI instrument error test on the Dynon. The Dynon ASI was within 1 knot from 230 knots all the way down to 40 knots so I know the Dynon ASI sensor is accurate.
- I compared my Dynon's pressure altitude reading on the ground while set to 29.92 to an airplane that is known good at the same elevation. His airplane has both a mechanical Alt and a D100 like mine. I only have the D100. Both our pressure altitudes were the same.
- I used the manometer to apply 35" w/c vacuum to the static system after setting the Dynon to report 0ft altitude and I got exactly 2500ft.
- I tried a test flight where I applied a 2"x2" square piece of aluminum tape to the side of the fuse and allowing it to ramp up and fair in the front edge of the static port without covering the hole. I honestly think this made it worse instead of better.
One possible theory is that I have my vinyl N numbers right in front of the static ports and that these are causing some sort of turbulence creating the error?
What says the guru's???
Here are some pics of the install and ports:
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