[BHunt]

Are there any glass manufacturers that have software that can use 3 AHRS? For example, the panel looks at all 3, if one is out of whack, it benches it. With only 2 AHRS, if one goes bad, how do you know which one it is?

 

[Auburntsts]

With only 2 AHRS, if one goes bad, how do you know which one it is?

The same way if you only have one AHRS: Air Data and/or GPS/magnetic crosscheck. Although in reality, multiple AHRS talk amongst themselves and figure which one is bad without you having to do anything.

 

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G3X

G3X will now

 

[Dynon]

The SkyView system will support up to four AHRS modules.

If you have two or more AHRS units, what it does do is visually show you the two disagreeing AHRS units on the screen at the same time, and you can vote one out manually. You use your pilot training to decide which one is likely invalid. For instance, if heading isn't moving much on either one, but one shows a crazy bank or turn rate, then you'd vote that one out. As far as we know, SkyView is the only experimental EFIS that has this feature.

In all honesty, we didn't think many people would actually install (3) AHRS units, so writing automatic voting software seemed over the top. Two AHRS units are pretty common.

All of this is covered in the SkyView Pilot's User Guide on page 4-18.

 

[BHunt]

The SkyView system will support up to four AHRS modules.

If you have two or more AHRS units, what it does do is visually show you the two disagreeing AHRS units on the screen at the same time, and you can vote one out manually. You use your pilot training to decide which one is likely invalid. For instance, if heading isn't moving much on either one, but one shows a crazy bank or turn rate, then you'd vote that one out. As far as we know, SkyView is the only experimental EFIS that has this feature.

In all honesty, we didn't think many people would actually install (3) AHRS units, so writing automatic voting software seemed over the top. Two AHRS units are pretty common.

So, if I have 3 AHRS and one disagrees, will it say "2 AHRS say this, and one says this"?

You use your pilot training to decide which one is likely invalid.

Valid, I just thought it would be pretty Gucci if these smart EFISs had a way of determining an invalid solution in a triple AHRS config. Where if one was reading different, you would get a warning, and the panel would select the two units that agree and would kick out the disagreeing unit. If a subsequent unit fails, then you have to play tie breaker. I understand this is just another redundancy layer, just thought it could be useful, especially if in IMC.

Another option, I suppose, would be to install a D10A and use it as a tiebreaker with a 2 AHRS config.