GI-275 upgrade advice

[Bryan G]

I am officially scheduled for a dual GI-275 install in my M20F, expecting first week in November but subject to change…hopefully for the better!

Current panel has two 106As, one driven by the GNS430W and the other by my SL30. From what I’ve read and what I was told, I could get rid of both 106s if I wanted, and they could tie the SL30 to the HSI as a backup. The shop will give me 800/ea for the 106s, but he said they will sell for a bit more if I sold them online.

So my question, should I keep one 106A for my SL30? And should I buy the second battery for the HSI? I’m between 3 different paths:

1. keep 106 but no battery, 2. Keep 106 and buy battery, 3. Sell both 106s and buy battery

Thanks for the advice!

[smwash02]

I just put in dual 275s and would suggest you do the following:

1) Ensure they install a GPSS switch for you

2) Ensure they install a manual failover switch

3) Get the 2nd battery for your HSI and ensure it can be an ADI failover. I believe the battery is required for this.

4) Keep a 106 (as did I) for the SL30.

My HSI 275 can show me HSI/CDI from both of my GPSes with the 2nd GPS also outputting on the 106. I'm not sure if you'll be able to do that with a 430/SL30, but it might. I've forgotten the wiring diagrams at this point.

Edited July 9, 2022 by smwash02

[Ragsf15e]

3 minutes ago, smwash02 said:

I just put in dual 275s and would suggest you do the following:

1) Ensure they install a GPSS switch for you

2) Ensure they install a manual failover switch

3) Get the 2nd battery for your HSI and ensure it can be an ADI failover. I believe the battery is required for this.

4) Keep a 106 (as did I) for the SL30.

My HSI 275 can show me HSI/CDI from both of my GPSes with the 2nd GPS also outputting on the 106. I'm not sure if you'll be able to do that with a 430/SL30, but it might. I've forgotten the wiring diagrams at this point.

Personally I’d do most of this except ditch both 106s.  You’d have to have several separate failures that also didn’t affect the sl30 / gi106 in order to actually use the remaining 106.  Also there’s a simple display of vor/localizer deviation on the sl30 display.  
Definitely get the battery.

Depending on budget, you now have the two old 106 holes… another -275 to act as traffic/weather?  How about something more important (and expensive) edm900, gi-275eis, or cgr30p and a cgr 30.  Engine monitor would be very good for your setup and you’ve now got room.

[Ragsf15e]

One other thing, I have a very similar panel to you, Gns430w, sl30, dual g5s, gi106.  I was told I have to keep the 106 with the sl30/g5combo which I now don’t think is correct.  Anyway, I never use the 106 other that monthly vor test. I really don’t think you need it.

I do have a primary engine monitor and that’s where i think you should use the 106 holes.

(my gi106 is bottom left of the panel, outside the pic)

[Bryan G]

7 minutes ago, Ragsf15e said:

Personally I’d do most of this except ditch both 106s.  You’d have to have several separate failures that also didn’t affect the sl30 / gi106 in order to actually use the remaining 106.  Also there’s a simple display of vor/localizer deviation on the sl30 display.  
Definitely get the battery.

Depending on budget, you now have the two old 106 holes… another -275 to act as traffic/weather?  How about something more important (and expensive) edm900, gi-275eis, or cgr30p and a cgr 30.  Engine monitor would be very good for your setup and you’ve now got room.

That’s right, I forgot the SL30 has the localizer display. I’m installing a CGR-30p/c stack pilot side, taking advantage of the Oshkosh discounts at the show. Excited to have the engine data on the pilot side.

Edited July 9, 2022 by Bryan G

[David Lloyd]

1 hour ago, smwash02 said:

I just put in dual 275s and would suggest you do the following:

1) Ensure they install a GPSS switch for you

2) Ensure they install a manual failover switch

3) Get the 2nd battery for your HSI and ensure it can be an ADI failover. I believe the battery is required for this.

4) Keep a 106 (as did I) for the SL30.

My HSI 275 can show me HSI/CDI from both of my GPSes with the 2nd GPS also outputting on the 106. I'm not sure if you'll be able to do that with a 430/SL30, but it might. I've forgotten the wiring diagrams at this point.

1. Absolutely, I regret not doing so.

2. This is mandatory if 275s are installed as primaries. 

3. Yes, although not sure it is required.

4. Nope, my only indicators are the 275s.

[Ragsf15e]

2 hours ago, Bryan G said:

That’s right, I forgot the SL30 has the localizer display. I’m installing a CGR-30p/c stack pilot side, taking advantage of the Oshkosh discounts at the show. Excited to have the engine data on the pilot side.

Yeah having the primary engine data on good displays and exportable to a computer is awesome.  Historical data really helps identify new issues and isolate problems.

[Bryan G]

3 hours ago, smwash02 said:

I just put in dual 275s and would suggest you do the following:

1) Ensure they install a GPSS switch for you

2) Ensure they install a manual failover switch

3) Get the 2nd battery for your HSI and ensure it can be an ADI failover. I believe the battery is required for this.

4) Keep a 106 (as did I) for the SL30.

My HSI 275 can show me HSI/CDI from both of my GPSes with the 2nd GPS also outputting on the 106. I'm not sure if you'll be able to do that with a 430/SL30, but it might. I've forgotten the wiring diagrams at this point.

Thanks for the advice. So the manual failover switch isn’t standard? Here is a screen grab of the quote with the work to be done, the GPSS switch will be internal…is that what you mean by GPSS switch or are you recommending another physical switch?

[David Lloyd]

About a year ago Garmin move the GPSS button to the top of the menu tree making access much easier.  At the same time they made a provision to install a dedicated switch to turn on or off the GPSS. This is what you will want to add.

I went with the synthetic vision for the flight path marker.

[smwash02]

9 hours ago, Bryan G said:

Thanks for the advice. So the manual failover switch isn’t standard? Here is a screen grab of the quote with the work to be done, the GPSS switch will be internal…is that what you mean by GPSS switch or are you recommending another physical switch?

They added provisions in the firmware for a physical switch about a year ago. It's installed on the panel so you can quickly switch between heading and GPSS. It's extremely beneficial.

[Bryan G]

It’s been incredibly useful having the ST-901, I definitely need to consider this. My google skills are failing me, I can’t find the PN for the physical GPSS switch. Garmin refers to it online but I can’t find it…

I know the software was updated and it’s much easier to select GPSS now, but if the GPSS switch is the Garmin GCU 485, might be a bit out of my price range for what I’m looking to do.

Edited July 10, 2022 by Bryan G

[carusoam]

Be very sure of the fail-over process…

Be able to prove to yourself that one system truly backs up the other… and vice versa…

There is an example of an MSer around here that proved the one failure affected both displays…

 

It is hard to tell when everything is working normally…

Installation planning is the time to get all of the details straight…

Our MSer with the problem bought the plane with everything installed already… prior owner didn’t know about the issue…

Great panel when everything is linked properly!

Best regards,

-a-

[David Lloyd]

5 hours ago, Bryan G said:

It’s been incredibly useful having the ST-901, I definitely need to consider this. My google skills are failing me, I can’t find the PN for the physical GPSS switch. Garmin refers to it online but I can’t find it…

I know the software was updated and it’s much easier to select GPSS now, but if the GPSS switch is the Garmin GCU 485, might be a bit out of my price range for what I’m looking to do.

Shop will install a simple toggle switch to do that, just a few dollars.

[smwash02]

3 hours ago, David Lloyd said:

Shop will install a simple toggle switch to do that, just a few dollars.

It's just a simple toggle switch as David has said.

[gmonnig]

On 7/9/2022 at 11:27 AM, Bryan G said:

That’s right, I forgot the SL30 has the localizer display. I’m installing a CGR-30p/c stack pilot side, taking advantage of the Oshkosh discounts at the show. Excited to have the engine data on the pilot side.

Man, sounds like we are gonna have the same setup. I too am going to do CGR30P&C on the pilot side and all CDI needles removed. I'm scheduled for Oct 24th to get my GI-275s installed along with my remote transponder. I won't have a single thing on the copilot side. Probably just put in a glovebox for phones and an iPad mount for the "Boss" in the left seat. I'll have plenty of space in the center stack for the gfc500 when the bank account replenishes.