GI275 AI and G5 HSI?

[zuutroy]

I've been having KI-256 troubles lately and I think it's time to say goodbye. As the G5 AI is no good for driving the KFC150, I'm limited to putting a GI-275 in there unless I want to change the autopilot too. I have a G5 HSI downstairs and I'm wondering if this is a pairing that could work? I know they won't communicate and they're essentially independent systems but so are the 256 and the G5 at present. It's a bit of an ugly solution....if it's even legal?

I asked one shop for a quote here in Europe and they said they didn't like the idea (and something about STC approval....I don't really understand all this stuff) and I should go for another G5 and the GFC 500 or rip out the G5 and get dual 275s. If I went the dual 275 route, I guess the G5 could be sold on?

Opinions welcome!

[PilotX]

Dual GI275s are great. The HSI/MFD is far more capable than the G5 as an HSI, my previous plane had dual G5s. I didn't try to run the KFC150 with GI275 as I put in the GFC500 at the same time. Good luck.

Edited September 11, 2021 by PilotX
I spell bad.

[Mooney in Oz]

32 minutes ago, PilotX said:

Good lick.

Where?

Sorry, I couldn't resist 

[PilotX]

1 hour ago, Mooney in Oz said:

Where?

Sorry, I couldn't resist 

Fixed it but good catch.

[PT20J]

There should be no technical reason why it would not work, but I’ve noticed that some of Garmin’s STC limitations are head scratchers. I’d ask the shop to show you explicitly why the STC won’t allow it. It might be an interpretation rather than a limitation. Garmin makes so many devices now that certifying every combination is just too expensive. Garmin’s position is that you have to follow the STCs exactly if that is the basis for installation approval. So, in the USA, any other configuration requires a FAA field approval. Not sure about Europe.

But the GI 275 has more features and a much sharper display than the G5, plus you can get AHRS redundancy. If you put it in the same panel with a G5, you will probably decide to upgrade the G5 at some point. If it were me, I’d install dual 275s and sell the G5.

Skip

[David Lloyd]

What Skip said.  After seeing a G5/GI275 combo in action you would wonder why you made that decision.  Conversely, after seeing dual Gi275S in action you would be thanking yourself for that decision.

[OR75]

Two STCs , I don’t see an incompatibility but need to ask the installing shop if it sees one 

G5 provides AHRS redundancy as well although not automatic . I have seen the thread on  2 GI275 going blank, and prefer to have two truly independent systems 

[EricJ]

33 minutes ago, OR75 said:

Two STCs , I don’t see an incompatibility but need to ask the installing shop if it sees one 

G5 provides AHRS redundancy as well although not automatic . I have seen the thread on  2 GI275 going blank, and prefer to have two truly independent systems 

I'm putting in a 2nd G5 to replace my attitude indicator and add to the existing G5 HSI.    The ease to switch a G5 between being an AI or HSI and not having to rely on whatever mystery backup limitations or strategies or selectibility the 275s wind up with made it an easy decision.    I don't need or really want whatever extras the 275s might bring to those functions, although I am looking at replacing my CDI with one in the future.  It looks like a good option for that function.

[Aerodon]

I think Garmin give (gave) a bit of a discount when buying pair.  My local avionics shop will give a price break on the second one, because it makes it a much easier install - buy the Garmin adaptor plates to mount in a KI256 hole, and no GAD29B to install.

And if you are challenged for panel space. the GI-275 will control a remote transponder.

 

Aerodon

[Warren]

9 hours ago, Aerodon said:

And if you are challenged for panel space. the GI-275 will control a remote transponder.

This is only true if you buy an additional GI275 as a MFD.  The ADI and HSI/Backup ADI cannot be configured to control a transponder per the STC.