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garmin G3X touch align problem

ALMARTON

Well Known Member
Dear folks I've got my RV7A with 41 hours of total flight time using the G3X Touch dual GDUs 460 .

However during my last flight after about 30 minutes cruising completely leveled at 7500ft on nice and normal day I got the message AHRS ALIGN and the EFIS was showing me in a step bank curve although I was completely leveled.

I tried to boot it up to ALIGN but with no success. Turned off and on the auxiliary battery everything did no good it continue to malfunction an show an erroneous attitude untill the end of flight. But in the next flight it worked fine.

If them I needed the EFIS to show me my attitude in a emergency situation I would be in serious trouble.

So I ask -

What could have happened? Does it need to be changed? Can I put a backup AHRS that would engage automatically if one fails to align?

I apprecciatte all help because I can't stay with a expensive top of line System like Garmin G3X that would put me in life risk in case I inadvertently get into an IFR situation.

Pictures of the inflight warning that lasted throught the entire flight (note the attitude it indicates despite I was completely leveled)

AHRS%201.jpg


Thanks in advance.
 
Last edited:
Dear folks I've got my RV7A with 41 hours of total flight time using the G3X Touch dual GDUs 460 .

However during my last flight after about 30 minutes cruising completely leveled at 7500ft on nice and normal day I got the message AHRS ALIGN and the EFIS was showing me in a step bank curve although I was completely leveled.

I tried to boot it up to ALIGN but with no success. Turned off and on the auxiliary battery everything did no good it continue to malfunction an show an erroneous attitude untill the end of flight. But in the next flight it worked fine.

If them I needed the EFIS to show me my attitude in a emergency situation I would be in serious trouble.

So I ask -

What could have happened? Does it need to be changed? Can I put a backup AHRS that would engage automatically if one fails to align?

I apprecciatte all help because I can't stay with a expensive top of line System like Garmin G3X that would put me in life risk in case I inadvertently get into an IFR situation.

Pictures of the inflight warning that lasted throught the entire flight (note the attitude it indicates despite I was completely leveled)

AHRS%201.jpg


Thanks in advance.

Hello Alexandre,

We received your email this morning after you posted here.

We are happy to work with you to determine what might have caused this.

The GSU 25 ADAHRS is very reliable, and of the thousands of GSU 25 ADAHRS units fielded since the release of this product in 2013, we can't recall ever hearing that one wouldn't complete alignment in flight, so we will certainly be reviewing the flight data log and installation. Failure of one of the many ADAHRS internal sensors is, however, always a possibility.

Probably the most troubling aspect of this posting is the claim that the flagging and loss of the use of a single device in a large and complex system would put your life in danger in IMC. You don't say that you plan to intentionally fly in IMC, but we hope that if you do, you are properly equipped to do so.

A second ADAHRS would have prevented loss of attitude on the primary flight display in this example, but even someone with a multiple display, multiple ADAHRS system must have a backup instrument for at least attitude and be prepared to use it if needed or shouldn't consider flying in IMC conditions.

Thanks,
Steve
 
.....A second ADAHRS would have prevented loss of attitude on the primary flight display in this example, but even someone with a multiple display, multiple ADAHRS system must have a backup instrument for at least attitude and be prepared to use it if needed or shouldn't consider flying in IMC conditions.
Steve

Is having two independent EFIS, both with independent backup batteries, two ADAHRS, all networked together not sufficient for IMC? Are you saying there should be a 3rd attitude indicator? Actually I have that because of IPAD and Foreflight but that was a pleasant extra, not originally planned for.
 
Is having two independent EFIS, both with independent backup batteries, two ADAHRS, all networked together not sufficient for IMC? Are you saying there should be a 3rd attitude indicator? Actually I have that because of IPAD and Foreflight but that was a pleasant extra, not originally planned for.

There is no one correct answer. Independent dual failures can happen, just statistically very unlikely. But what caught my eye is "networked together". Are your two systems really independent? Can a software error propagate between systems? Or worse, do they use the same software?
 
Is having two independent EFIS, both with independent backup batteries, two ADAHRS, all networked together not sufficient for IMC? Are you saying there should be a 3rd attitude indicator?

This is something that has been discussed quite a bit. Yes, there is a possible failure scenario when using two same-software, connected/communicating ADAHRS systems. The recommendation is to have one backup with different software so that an issue in the code does not cause you to loose all your attitude sources. The G5 was specifically designed to meet this need.

In summary, what people are saying is that you should have two independent ADAHRS systems when flying IMC.
 
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