ADHARS malfunction

[rvrobert]

I have recently installed the 4.0 update to an RV9A with dual 10” skyview screens and dual ADHARS.

I have been getting cross check errors regarding the airspeed. When I compared the two there is about 13 Kts difference and there is about 4 degrees difference in the compass heading.

I did a zero airspeed cal. and did not see any change in the comparison. I then changed the source of the ADHARS and did another zero airspeed cal. and still no change. I redid the process again but prior to the cal. I reset to factory. Still no change.

Now for some reason the auto pilot is now not working (2 axis).

Can you suggest what I do now?

PS

Prior to installing the 4.0 update the system was turning itself off in flight, (no power countdown just blank screens.) After turning them back on they would operate normally. However this has happened on a few occasions. That’s why I updated the system as I thought it was a software problem.

 

[dynonsupport]

Well, the turning off and the cross-check errors are completely independent things. Give us a call at 425-402-0433 to talk about the ADAHRS issues, though.

 

[skydancer]

You are not the only one having compass heading issues. My friend at Chino airport has the heading off by 20 degrees since day one, and he hasn't got the problem solved yet.

Mine was off between 15 to 45 degree, one would work fine, and the other was off for 15 to 45 degree, and it switched around, some times it's 200, some times it's 201. That was back in the firmware 3.1--3.3 period, during that time, there was no "compare" feature build in the system. I spent hours calibrating at Compass rose at the airport without any result. Now since I've upgraded to 5.1, the heading is only off off 6 degrees between the two ADAHRS, I think I can live with it. 

My problem was posted a year ago, and Dynon didn't come up with a solution. One time I requested to talk to network engineer because I thought the network guy might come up with a better answer, but the guy who I talked to said, they have spent too much time dealing with my problem and rejected my request, pretty much ask me to F-off, so I stopped asking for help. Can you imaging how dangerous it is making a trip to Alaska with this unsolved problem in my RV-7.

I did send in my 200 for repair at the very beginning of the troubleshoot, before I even learned the symptom was actaully switching around between the two ADAHRS.

The hardest part is, the problem doesn't stay in one unit. So, it's definitely not an installation issue.

So the bottom line is, did Dynon solved your problem? I disappeared from this forum for about a year, because Dynon couldn't solve my problem, and now I'm coming back to learn how you guys are doing with your system.

 

[airguy]

Question on this - is this heading disagreement something that is only showing up on using with dual ADAHRS? The ones with only a single ADAHRS (even feeding dual screens), it seems like I don't hear about any problems there, is that correct?

 

[skydancer]

If your ADAHRS heading matches other reference source in your airplane (for examle --- Magnetic compass, GPS or DG), then you are ok, nothing needs to be worried about.

My SV-1000 is on it's way to Dynon per latest service bulletin recall, I hope that's related to my ADAHRS issue, which has been dragging me for over a year without a fix, I'm keeping my finger crossed.

 

[Dynon]

Jay - We actually did find a bug in SkyView's calibration routine, in part thanks to your data and feedback. See http://www.dynonavionics.com/docs/WhatsNew_SkyView.html for more details. You need to be running 5.1, and recalibrate one final time, for a correct cal to take on both ADAHRS. If you're working OK today, of course, no need to change anything. Our support staff did send you an email when 5.1 was released, by the way, since they'd been working with you offline.

 

[Dynon]

airguy - correct, the "cross check" messages happen when flight instruments across multiple ADAHRS disagree. And the calibration issue previously described only affects systems with more than on ADAHRS (and then, only some people, technically).