my IAS (indicated Airspeed) and IA (indicated Altitude) are off.
When slow, near Stallspeed, everything is good. Speed and Altitude is dead on.
When going faster, the IAS is 15 knots to low and the IA is 300 ft low.
I did the TAS calibration (flying squares in the sky) a couple of times. The error is linear from 100-150 KIAS (10 kts increments tested).
Altitude was crosschecked with GPS Alt which was my Alt reference.
Why That the error is linear and not exponentially with raising speeds is another question.
Here is my math.
Pitot & Static is a closed system.
Too low IA read out means higher pressure at the static port (higher than ambient static pressure).
As IAS is the result from total pressure (Pitot) minus static pressure, the too low IAS i see is the normal result.
I figure that the static port is in a area of high pressure due to airflow around the fuselage.
Build something (damms, vanes, obstacles, .....call is what you want) in front of the static ports to create a low pressure area behind.
Try size and form until i get it right and static port gets correct ambient pressure.
There are numerous threads about this. But to give me a headstart, i kindly ask to post pictures from your solutions. I try to get an idea of mounting position, height, material, how attached, ..........of what you did.
If you could post the changes (IAS, IA) it produced would be most excellent.
Thanks in advance!!
p.s. i think i got it figured out, but if i am totally off or on the wrong path here, i appreciate any directive hints.
p.p.s fixed pitch sensenich GA prop gave me 166 KTAS @ 2500RPM,