I finally got the GMU 11 installed in an area with no interference; previously, it was lower in the tailcone, and the rudder cables were magnetized enough that the interference test failed.
It is now mounted on the Van's bracket in the top of the tailcone just aft of the baggage wall. Passed easily with no issues at all.
So I went to KMZZ to calibrate again using the compass rose.
Calibrated easily on the first try. Lined up on RWY22 for departure, heading reads correct.
Flying back, I lined up with east/west and N/S roads. My heading consistently reads 4-5 degrees right. Flying south, I read 185. Same for all directions. This is the same issue I had with the previous mounting location, and I assumed it was because of the interference failure.
I have not emailed g3expert yet, as I wanted to see if others had seen this, or if there is something I am missing. My understanding is that the EFIS / magnetometer accounts for declination automatically, so this shouldn't be it. I am pretty certain I was flying south / west, etc, as here in Indiana the roads are laid out pretty darn straight for the most part. This error is consistent, and repeatable.
This error causes other weird data; the displayed winds on the EFIS are way off of what weather is actually reporting.
Thanks in advance for any thoughts / assistance.
It is now mounted on the Van's bracket in the top of the tailcone just aft of the baggage wall. Passed easily with no issues at all.
So I went to KMZZ to calibrate again using the compass rose.
Calibrated easily on the first try. Lined up on RWY22 for departure, heading reads correct.
Flying back, I lined up with east/west and N/S roads. My heading consistently reads 4-5 degrees right. Flying south, I read 185. Same for all directions. This is the same issue I had with the previous mounting location, and I assumed it was because of the interference failure.
I have not emailed g3expert yet, as I wanted to see if others had seen this, or if there is something I am missing. My understanding is that the EFIS / magnetometer accounts for declination automatically, so this shouldn't be it. I am pretty certain I was flying south / west, etc, as here in Indiana the roads are laid out pretty darn straight for the most part. This error is consistent, and repeatable.
This error causes other weird data; the displayed winds on the EFIS are way off of what weather is actually reporting.
Thanks in advance for any thoughts / assistance.