G5 reversionary with GFC500

[CT583]

I had a question come up during my instrument checkride today that I could not answer.
...You have Dual G5 with the GFC500 autopilot, if the AI(top) G5 fails, does the HSI(bottom) G5 still drive the Autopilot when it reverts to Reversionary mode and acts as the AI?

I basically answered. I don’t know, it may, but I wouldn’t exactly trust it. Apparently that was acceptable.
Well it turns out he didn’t know the answer either and we searched around after the instrument oral.

Do any of you Garmin Pros know if the GFC-500 is able to source the correct data from the HSI G5?

 

[Salty]

Yes. It'll work just fine. Technically, the HSI is the one driving the autopilot, you're just using the AI to set the bugs, which you can do with the HSI also.

And congrats!

 

[Walboy]

That was a good question and it's refreshing that he admitted he didn't know either.

I think one of the difficulties in instrument instruction these days is not knowing the all different failure modes from all the possible combinations of avionics and how to recognize them. And when you "think" you know, you might not know for sure.

 

[CT583]

Thank you! It was a tough test. 30kt winds, gusty and turbulence. A perfect day for a checkride lol

It makes sense that the HSI drives it.
Is there somewhere this is printed?

I looked through my manual for the G5/GFC500 and didn’t pick it up, but then again it was more of a scan.

 

[Salty]

Thank you! It was a tough test. 30kt winds, gusty and turbulence. A perfect day for a checkride lol

It makes sense that the HSI drives it.
Is there somewhere this is printed?

I looked through my manual for the G5/GFC500 and didn’t pick it up, but then again it was more of a scan.

Try it next time you're at the plane. I'm kinda surprised he didn't fail it on you to see.

 

[Gary Ward]

Try it next time you're at the plane. I'm kinda surprised he didn't fail it on you to see.

It is a good question and like Salty said that was the first thing that came to my mind I will try it next time I am flying.

But then I thought how do I turn off it off? I would have to turn off my avionic switch to turn off the G5 and then everything else would turn off. Do you hold a button in on the G5?

From what I read this question came up during the oral part of the checkride.

 

[Salty]

It is a good question and like Salty said that was the first thing that came to my mind I will try it next time I am flying.

But then I thought how do I turn off it off? I would have to turn off my avionic switch to turn off the G5 and then everything else would turn off. Do you hold a button in on the G5?

From what I read this question came up during the oral part of the checkride.

Yes, hold the button and it will turn off.

 

[Gary Ward]

That was a good question and it's refreshing that he admitted he didn't know either.

I think one of the difficulties in instrument instruction these days is not knowing the all different failure modes from all the possible combinations of avionics and how to recognize them. And when you "think" you know, you might not know for sure.

I agree, my older DPE was un interested in my panel. They only required me to fly approaches by hand and the AP was not talked about or used. They relied on me to be able to program the panel for the approach flown. It was not the time or place to experiment.

I have a G650/ 255, 2-g5s, gfc500 gtx345 and gma345 audio panel. They didn't know anything about it and didn't want to know. I passed my IFR checkride without a question about my panel.

They did check for a current pitot static check and ELT battery.

 

[CT583]

We have the same panel.

I think it’s a good practice for a DPE to challenge you on what you have available in the aircraft. He was sure to test me on the use of the GFC500 and available functions of the GTN650.

I think that I’m confident in the HSI operating. I’ll try it next time I fly.
If any of you try it, report back, I’d like to hear about it!!