GI 275 install questions

[Pictreed]

Has anyone installed a 275? I think If Garmin doesn't do it you don't get SVT. I know lots of people have installed the G5 but I haven't heard of anyone installing the 275.

My next question is has anyone used both? The 275 seems to have too much info in one spot. However, it is more compatible and looks really good.

My IA has the G5 so I need to see if I can fly his plane before I decide.

[toto]

The big advantage to the G5 over the 275 is the battery life. If you lose ship’s power in the 275 you have something like 60 minutes of battery, while the G5 is more like four hours. 

The G5 doesn’t have synthetic vision, so if that’s important to you then the G5 will be a disappointment. 

I like the longer battery life of the G5, and I also like the square face, which matches better the rest of my panel. 

[Jake@BevanAviation]

New GI275's come with a 10 hour trial of SVT.  If you like it and want to add it there is a unlock that is needed.    GI275's do a lot more vs G5 and interface with more equipment vs G5.  Depending on the equipment in the aircraft the GI275 could have a advantage over the G5.

[EricJ]

I have dual G5s and love them.   I've flown with 275s as well, and they're very nice and do a lot of interesting things, but I think they try to cram too much into the tiny space of a 3" round gauge.   The square display on the G5 looks less cluttered to me. 

I'm looking at replacing my #2 nav and ancient CDI with a modern nav/com and use a basic 275 for the CDI, and connect it to my IFD to add the map display, etc.   I think they're good for that sort of thing, although it's an expensive solution for that task.

 

 

[DC_Brasil]

When I had to choose my backup attitude indicator I had the choice of G5 versus GI275, and chose the G5.

I had the opportunity to fly briefly with aGI275 equipped C172 and found that, although very capable, the 275 seems to be very small for the amount of information it can display. It felt crowded and polluted (for an ADI). I think the VOR/CDI/MFD GI275 is good and never seen the engine version in person. 

My thoughts were: I will have to rely on that thing if my G3X fail, so let's make sure I have a clear easy picture of attitude with less clutter in front of me.

But that thought is for a BACKUP instrument. 

If you're choosing it for primary, then other considerations apply: which AP, navigator and other equipment you'll have installed. The GI275 is way more compatible with other things: for example it has a version that can drive analog attitude driven autopilots like the KAP 150.

[Utah20Gflyer]

On 3/10/2025 at 10:36 PM, Pictreed said:

Has anyone installed a 275? I think If Garmin doesn't do it you don't get SVT. I know lots of people have installed the G5 but I haven't heard of anyone installing the 275.

My next question is has anyone used both? The 275 seems to have too much info in one spot. However, it is more compatible and looks really good.

My IA has the G5 so I need to see if I can fly his plane before I decide.

My understanding is the GI 275 is only supposed to be installed by Garmin approved shops.  The G5 on the other hand can be installed by any A&P.   

[Utah20Gflyer]

On 3/10/2025 at 10:58 PM, toto said:

The big advantage to the G5 over the 275 is the battery life. If you lose ship’s power in the 275 you have something like 60 minutes of battery, while the G5 is more like four hours. 

The G5 doesn’t have synthetic vision, so if that’s important to you then the G5 will be a disappointment. 

I like the longer battery life of the G5, and I also like the square face, which matches better the rest of my panel. 

My last battery test on my GI 275 went a little over 90 minutes.   4 hours would be nice but an hour and a half seems perfectly adequate to find a place to land at my leisure.  

[PeteMc]

16 minutes ago, Utah20Gflyer said:

My understanding is the GI 275 is only supposed to be installed by Garmin approved shops.

I'm not sure of the specific units, but some GI 275 variants can be installed by an AP, others need to be installed in a Garmin shop.  I think the difference might be with the ADAHRS and Auto Pilot versions. 

 

[Jake@BevanAviation]

Base unit GI275's can be purchased over the count and installed by a AP.  ADAHRS and ADAHRS+AP units need to be purchased via a Garmin dealer.  Base units are typically used for CDI, MFD, HSI, EIS functions.  They do not have the second connector that is used for legacy autopilot interface and do not have ADAHRS functions.

[Pictreed]

1 hour ago, Jake@BevanAviation said:

Base unit GI275's can be purchased over the count and installed by a AP.  ADAHRS and ADAHRS+AP units need to be purchased via a Garmin dealer.  Base units are typically used for CDI, MFD, HSI, EIS functions.  They do not have the second connector that is used for legacy autopilot interface and do not have ADAHRS functions.

This is what I thought too.

I'll get a quote for the 275 install but, based on the work quality from my GPS install, I'd prefer doing it myself unless I can find a good shop I can trust which seems to be difficult.

Most likely I'll be doing the dual G5's recessed in the panel.

[William Munney]

I have the Garmin GI275 installed as a backup attitude indicator.  It also drives the new GFC500 Autopilot or I would have installed the G5.  The Gi275 is a beautiful instrument but it’s crowded.  I wish it had a bigger display and that it was a square/ rectangle display. The 60-90 min battery is MORE than enough time to get on the ground with a PFD or electrical failure.

Thankfully, the TKS Ovations have TWO alternators and ,of course, TWO batteries so total electrical failure is a remote possibility.

Avionics shops are currently out their minds with install prices.  My quotes from around the nation varied by +/- 10K for and AP/ GI275 install.

[Neshi]

I have had both the G5 in the F and the 275 in the K both installed with a gtn650xi.

The choice for the 275 in the second plane was I have a working KFC150 and the g5 did not play nicly with it.

I opted for SVT as when choosing options it was only $500 more even if I did not think it was needed. (I've come to love it puting the flight path vector on the end of the runway helps when going into a field with a smaller width runway.)

as far as the information thing uless you are installing a gfc500 i just have a little strip with all i need in one place.

 

[Pictreed]

After a tough IMC in moderate rain for 2.5 hours last week I really want an AP. I'm leaning towards the GFC 500. I thought that worked with the G5? I think if the AP was installed the 275 might be better but that cross scan might have been more difficult flying it manually in the rough IMC. It's a hand full.

A couple avionics professionals looked at my currently installed equipment and the negative comments were from an Avionics shop and the positive comments was what my IA signed off of so I don't really want to go back to an Avionics shop. They have to make money and working on these legacy aircraft seem to take longer than what they're budgeted to do. So I'm leaning towards the G5.

[donkaye, MCFI]

 

On 3/25/2025 at 8:36 AM, William Munney said:

I have the Garmin GI275 installed as a backup attitude indicator.  It also drives the new GFC500 Autopilot or I would have installed the G5.  The Gi275 is a beautiful instrument but it’s crowded.  I wish it had a bigger display and that it was a square/ rectangle display. The 60-90 min battery is MORE than enough time to get on the ground with a PFD or electrical failure.

 

There must have been some other reason because the G5 has all the software for the GFC 500.  With an ADC the G5 displays DA automatically when on the ground and there is a data block for TAS.  I have flown full approaches in VFR conditions with the G500TXi turned off and all works as well as with it on.  Mine is hooked up as shown below except I have it connected to the GTN 750Xi instead of the GTN 650Xi.

I had the opportunity to fly with the GI275 with Syn Vision at the PPP a couple of weeks ago.  It is worth the $500 unlock cost, but I was not satisfied with the operation of the flight path marker as compared with it on the G500 TXi.  Whereas I can fly a perfect level 45° banked 360° with the TXi, the GI275 fpm was way too sensitive to do the same.

 

[PT20J]

1 hour ago, Pictreed said:

After a tough IMC in moderate rain for 2.5 hours last week I really want an AP. I'm leaning towards the GFC 500. I thought that worked with the G5? I think if the AP was installed the 275 might be better but that cross scan might have been more difficult flying it manually in the rough IMC. It's a hand full.

A couple avionics professionals looked at my currently installed equipment and the negative comments were from an Avionics shop and the positive comments was what my IA signed off of so I don't really want to go back to an Avionics shop. They have to make money and working on these legacy aircraft seem to take longer than what they're budgeted to do. So I'm leaning towards the G5.

If I were in your shoes, I'd get dual G5s and the GFC 500. That's going to be the lowest cost configuration and is perfectly adequate for safe, comfortable IFR. I would take it to a shop that had done GFC 500 installations on Mooneys so that they are not learning on your airplane.  

[DC_Brasil]

On 4/18/2025 at 8:45 PM, PT20J said:

If I were in your shoes, I'd get dual G5s and the GFC 500. That's going to be the lowest cost configuration and is perfectly adequate for safe, comfortable IFR. I would take it to a shop that had done GFC 500 installations on Mooneys so that they are not learning on your airplane.  

I second that. 

One other thing to consider: avionics installations have two things to take into account, which are parts and labor.

If you installations, let's say, a dual G5 today, and a new GPS in 18 months, you'll pay for all the time to disassemble and reassemble your panel now and, again, when you do another upgrade. So, if you're going to upgrade your panel, even if it is in phases, plan ahead what you think is going to be feasible in the near future.

This way, the shop can already have some of the wiring and spacing behind the panel in a way that will minimize costs in the near future.

Also, ask your shop for quotes for additional equipment (even if you aren't thinking of it now). Ut may be financially sound to invest in some equipment if the labor part will be roughly the same (once your panel is all exposed and wires being redone).

[Pinecone]

Agree. Plan out where you are going longer term and get them to put in the wiring for you final panel.   Otherwise, each phase you will pay to have the interior removed and lots of inspection panels and put back together.

One person I know did the dual G5s.  And flew that for a while.  Then got to fly a G3X Touch, so moved up keeping on of the G5s as the backup and mounting the second one on the right panel for the right seat person (both of the couple are pilots).

And even think about non-avionics things.  I had a cigarette lighter outlet installed in the back seat to power an oxygen concentrator.  And to run a wire for a SureFly electronic mag.

[William Munney]

I honestly can’t remember why I went with the GI275 vs the G5.  Talked to Garmin.  Talked to Maxwell.  End result was the GI275 driving the GFC500.  No problems.  Very happy with GFC 500 and its integration with the GI275 and the G500 TXi…..GTN 750.

[William Munney]

What works for us:

G500 TXi, GTN 750, GNS 530 (WAAS), GI 275 Standby, GFC 500 Auto-pilot.  And, the IPad.  (Don’t forget the USB ports!)

Starting at 7500’ in cruise yesterday, we were able to GPS navigate to the IAF for the RNAV GPS approach, descend from cruise in VNAV to the IAF and also the subsequent published step downs, follow the approach course to intercept the GP (glide path) and then descend to minimums while working only the throttle, the gear and the flaps.  Occasionally the speedbrakes.  This is a complete game changer for GA.  The FMA’s (scoreboard) provide complete confidence in the workings of the AP by telling you at all times what pitch and roll and altitude modes are currently activated, and which ones are armed.

The missed approach was accomplished solely with the G/A button, the throttle, the gear and flap switches with the AP remaining engaged the entire time.  The airplane climbed to the missed approach altitude, leveled off, and entered the missed approach hold with no issue.

I recommend changing the default VNAV descent angle in the GTN750 from 3 degrees to 2 degrees or less.  Three degrees is too steep for piston airplanes without very low power settings and higher vertical speeds.  Two degrees or less results in cruise descent rates from about 400-600 fpm which is nice for passengers and power settings.

Two weeks ago we did the same in snow and ice (to minimums) giving the TKS system a workout.  (120 knot minimum when using this system)

This panel has satellite (and ADSB) weather which is nice because of the faster update rates but it’s not a MUST have.

If you are going to fly your airplane in the weather and/ or travel long distances in it.  I highly recommend moving your panel to the modern instruments.  And, as many others have said, it’s best if you can do it all at once.  It’s a functional, situational awareness and safety leap forward.

 

[wombat]

@William Munney It looks like you've probably got a GTX-345R in your panel which should provide ADS-B in as well.   I just link my iPad to the GTX-345-R for ADS-B, FIS-B and TIS-B input to see in ForeFlight.

 

So I'm wondering why you have the Stratus on the dash as well.

[William Munney]

The Stratus was in the airplane when i bought it.  Just using it as a backup now.

[PeteMc]

1 hour ago, William Munney said:

The Stratus was in the airplane when i bought it.  Just using it as a backup now.

Good guess that the prior owner had it before the ADS-B upgrade in the plane and also kept it as a backup.  Nice thing to have and just charge up before those days you know are going to be solid IMC.  Not sure I'd have it on or charging every flight (VMC) and wear out the battery.  

[jamesm]

I just wish that the G5 had bigger cursor or unique identifying  feature on cursor making it sticking out  easier to see and bigger font.