PT20J Posted July 26, 2021 Report Share Posted July 26, 2021 I'm curious if anyone with a G3X/G5 installation has had an inflight AHRS reversion, AHRS realignment, or MISCOMPARE annunciation and how you resolved it. Skip Quote Link to comment Share on other sites More sharing options...
Niko182 Posted July 26, 2021 Report Share Posted July 26, 2021 33 minutes ago, PT20J said: I'm curious if anyone with a G3X/G5 installation has had an inflight AHRS reversion, AHRS realignment, or MISCOMPARE annunciation and how you resolved it. Skip The only difference between my G5 and G3X is the altitude on the G5 shows about 20 ft higher than the G3X Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted July 26, 2021 Report Share Posted July 26, 2021 With the Dynon Skyview, I occasionally would get a miscompare annunciation that usually involved a combination of tight turns and/or G forces. A couple times were just turbulence related. One time taxiing on a rough surface while turning. A little bit of straight and level, the annunciation would go away. I expect pretty much the same with the GI-275s. Except not so many tight turns and Gs with the Mooney. Quote Link to comment Share on other sites More sharing options...
jamesm Posted July 27, 2021 Report Share Posted July 27, 2021 9 hours ago, PT20J said: I'm curious if anyone with a G3X/G5 installation has had an inflight AHRS reversion, AHRS realignment, or MISCOMPARE annunciation and how you resolved it. Skip Not sure if this applicable to your situation . ..... with two G5's installed and recent GFC 500 installed. I would get a "Attitude comparator" message from the G5 Data_Log file on the micro SD slot (with data logging enabled on the G5). In my case with 2 G5's EADI and G5 HSI was reverting back to the ADI prior to GFC500 install. I thought I had fixed this ADI reversion problem when I discovered an open CAN bus terminator and replaced it. This problem was very intermittent problem and very annoying because some flights it would fail and other flights it was fine very random problem. After changing the CAN bus terminator it seem to much more reliable but I still had my doubts in the back of my mind. It was only after the GFC500 install did it reveal that problem had not been fixed. We couldn't have never have diagnose the problem properly without the GFC500 being in the loop. The installer swapped G5 positions ADI with HSI. it worked flawless after that and the "Attitude comparator" message wasn't showing up in data_log file and no ADI reversion on the HSI G5. this meant that my original G5 (an oldest) ADI has a bad Attitude comparator or so it appears. My installer had mention to me that it could have been almost any Garmin device on the CAN bus loop giving the "Attitude comparator" message since most of the newer Garmin units have the AHRS circuitry embedded in them. It may sound simple but the more CAN devices (nodes) on the bus especially the GFC500 the more columns appear in the Data_log file. The 2 G5 installation with GMU11, GAD13, GAD29B configuration(before the GFC500 install) had no column for the "Attitude comparator" message which appears in the "Autopilot state" Column since it didn't exist at the time. Hope this helps, James '67C 1 Quote Link to comment Share on other sites More sharing options...
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