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Dual screen GRT HX anomaly

flytoboat

flytoboat

Well Known Member
Flying an RV10 today, fortunately in VFR, when with no warning the PFD went inverted. The maps were erratic and the auto pilot headed off course. Winds aloft went from quartering headwind at 60 kts to 260 kts headwind. We used my mini iPad to complete the flight and after shutdown the displays came back up normal. The flight home was uneventful. Lunch at Gaston's resort was excellent as usual:). Has anyone seen this happen before?
 
Yes, the owner got a couple shots of the screens and he plans to call GRT on Monday. After a search of the archives, I thought I'd post here to see if this has happened before. I think he is ready for a Mini AP for a backup. Would have been scary in IMC!
 
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BobTurner said:
Do you know if this was a single or dual ADHRS?
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Bob, it is a dual screen with dual ADHRS. The left screen went inverted (green on top, blue on bottom) as if we were flying up side down. The left screen was on the map page when this happened and the map was very erratic. We switched the right screen to PFD and it remained right side up with attitude, airspeed, VSI, altitude working correctly but the synthetic vision was erratic. Again, the winds aloft arrow went from a steady left quartering headwind at 60Kts to 270Kts headwind. He had recently loaded the sectional charts so we pulled the thumb drive for that with no change. We used my mini iPad with split screen Foreflight and stratus for backup attitude/GPS. Don.
 
flytoboat said:
Flying an RV10 today, fortunately in VFR, when with no warning the PFD went inverted. The maps were erratic and the auto pilot headed off course. Winds aloft went from quartering headwind at 60 kts to 260 kts headwind. We used my mini iPad to complete the flight and after shutdown the displays came back up normal. The flight home was uneventful. Lunch at Gaston's resort was excellent as usual:). Has anyone seen this happen before?
Click to expand...

This is a shot in the dark but have you checked the connections to the MAGNETOMETER for said display?

My SPECULATION is that if you are getting wild changes in heading some of the things you see MIGHT happen.

James
 
jclark said:
This is a shot in the dark but have you checked the connections to the MAGNETOMETER for said display?

My SPECULATION is that if you are getting wild changes in heading some of the things you see MIGHT happen.

James
Click to expand...

However, the ahrs uses a "calculated" mag solution, not just the raw data out of the magnetometer. So, the Magnetometer can be fine, but if you are able to confuse the ahrs, the calculated mag solution will be way off, as indicated by the crazy calculated winds. I've done it.
 
My WS and single AHRS has tumbled 4 times in the last 3 weeks. 3 times at boot and once in the air. Horizon spins and also the map spins. Reboots fixed except the one in the air. Like James said, when I get home from my 4000 mile xc, I will look hard at the magnetometer. I have not had a chance fo talk to GRT yet but I imagine they will be helpful as always.
 
Don,

This is just speculation on my part, but you mentioned you just loaded the charts. Seattle Avionics just made some pretty major updates to their package. We haven't seen anything unusual from it but it would be worth a check to see if that caused anything. Where were you flying?

The EFIS requires a reboot to detect charts on the USB stick, so if you remove the stick to see if the charts are causing an issue, you should reboot the display unit with the USB stick out of it. To do this, press and hold the outer softkeys simultaneously until the screen fades and the reboot process begins. You can do this in flight. This would also explain why it behaved normally on your way home, after you restarted the system without the stick. (Speculation only!)

I'll forward this thread to Jeff, our programmer, to see if he has any ideas. I'm glad you were VFR.
 
Thanks for everyone's replies. The owner has been in touch with the fine folks at GRT and they are troubleshooting.
For Katie: we removed the maps thumb drive in flight but didn't reboot. He put the thumb drive back in before start up on our way home and all was ok.
Don
 
Katie can correct me if I'm wrong, but I think holding in the far left and right buttons re-boots the display unit but not the ADHRS?
 
BobTurner said:
Katie can correct me if I'm wrong, but I think holding in the far left and right buttons re-boots the display unit but not the ADHRS?
Click to expand...

Yes, that's correct. To reboot the AHRS you need to cut power to it through the breaker or the avionics master.
 
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