G 3 vs dual G275

WDD

WDD

Final Approach
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Vintage Snazzy (so my adult children say)
If a person is putting in dual G 275s would at that point it make sense to just put in a G3 instead?
 
Shades of grey. Somewhat subjective and completely case-by-case considerations. Of course, also you have to assume one's aircraft is on the G3X Touch AML, if you're talking about a certified installation. Sometimes the cost of panel surgery is the difference maker. Garmin is good at pricing their offerings on tiers that are tantalizingly close to each other in certain parts of the upgrade ladder. The G3X Touch is not an option for my aircraft, but if it was, I would want to take the extra step for what that package offers above and beyond a pair of GI275. A PFD that size is a pretty big step up from a pair of 3 1/4" instruments, no matter how powerful they are.
 
if you are also looking for engine instruments then I say G3X if available. By the time you buy two G5s and a JPI you are a good way there. Buy omce cry once.
 
A GI275 AI/HSI pair runs around $9500. A 7" G3x plus a G5 (required backup) runs around $12k. Add in the additional panel surgery and I'd say the G3x+G5 is still a significant jump.
 
A G3X touch is a lot more than two 275s. But I’m biased. I have a G3X. Ask the other responders what they have.
 
WDD said:
What lead you to that choice vs a G3X or other options?
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If I went with the G3X it would have cost me an extra 6 grand to have the panel modified. With the 275's, I just used the existing holes. Besides, I like the 6 pack look.
 
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For my upgrade (hopefully finished this week) I started thinking I wanted two GI275s. But then I needed an EIS, so make it three. Then I saw all the MFD pages they offered and...I should get a fourth. And then I saw another skylane with a 10" display and thought, what the hell am I doing with all these 275s?

It definitely changed the feel of the project from "let's get some modern equipment in this plane," to "gut it and put in new everything." Once I crossed that line it was easy to go all the way to a G500TXi, GTN750, and GFC600. So, a bit of a slippery cliff. ;) But I've got a panel that should serve me for a very long time now.
 
A mechanic friend is building a panel with two 275s and a 760. Simple and functional. The 275s are too small for my eyes but it’s a nice compromise for a certificated airplane.
 
ServoB17 said:
For my upgrade (hopefully finished this week) I started thinking I wanted two GI275s. But then I needed an EIS, so make it three. Then I saw all the MFD pages they offered and...I should get a fourth. And then I saw another skylane with a 10" display and thought, what the hell am I doing with all these 275s?

It definitely changed the feel of the project from "let's get some modern equipment in this plane," to "gut it and put in new everything." Once I crossed that line it was easy to go all the way to a G500TXi, GTN750, and GFC600. So, a bit of a slippery cliff. ;) But I've got a panel that should serve me for a very long time now.
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Yeah, I put the brakes on the "might as well" thing. At some point, it doesn't make sense to spend more on avionics than the airframe is worth. 2 x GI-275's and a GTN 750 serve me well. I just didn't like the look at a big "TV" screen in front of me but to each his own I guess.
 
Joe_B1 said:
Yeah, I put the brakes on the "might as well" thing. At some point, it doesn't make sense to spend more on avionics than the airframe is worth. 2 x GI-275's and a GTN 750 serve me well. I just didn't like the look at a big "TV" screen in front of me but to each his own I guess.
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I agree. With how good the 275s are, you don't give up much in functionality and it's more "what would you rather look at?" For me it was: why would I want a bunch of circles when I could make the whole thing one big display?
 
If you’ve never had the opportunity to fly behind a G3X for a handful of hours you can’t know how simple it is to access information screens in a useful size with a touch of a finger. I go between my G3X Touch with remote comm, txp, and AP and a 6-pack of round instruments with digital engine gauges on the right side. I prefer the G3X. More info and it’s presented in a better format. They both get the job done, so it really is just about preference.
 
Okay, now I'm suffering from upgrade envy. Next week I'm upgrading the six pack with a King HSI and replacing the AI and HSI for a pair of GI-275s. I'm swapping the STEC 55x for a GFC-500. I thought about going the G500Txi route, and upgrading the GNS 530W with a GTN 750, but decided that I needed to save some money for my engine overhaul.

I may still do the G500Txi upgrade in the future and keep one of the GI-275s as a backup to the primary display.
 
Stewartb said:
The 275s are too small for my eyes but it’s a nice compromise for a certificated airplane.
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That - is a great point. G3X allows larger images/font? I’m using bifocals now - not going to get better.
 
Stewartb said:
The 275s are too small for my eyes but it’s a nice compromise for a certificated airplane.
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Is that an observation or an assumption? I checked out the 275s at OSH and they’re very readable, IMHO, especially compared with existing steam gauges. Actually, more readable than the G5s, I thought.

YVMV (your vision may vary) :)
 
Brad Z said:
Okay, now I'm suffering from upgrade envy. Next week I'm upgrading the six pack with a King HSI and replacing the AI and HSI for a pair of GI-275s. I'm swapping the STEC 55x for a GFC-500. I thought about going the G500Txi route, and upgrading the GNS 530W with a GTN 750, but decided that I needed to save some money for my engine overhaul.

I may still do the G500Txi upgrade in the future and keep one of the GI-275s as a backup to the primary display.
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It's not the size of the instrument.... wait.....


Llewtrah381 said:
Is that an observation or an assumption? I checked out the 275s at OSH and they’re very readable, IMHO, especially compared with existing steam gauges. Actually, more readable than the G5s, I thought.

YVMV (your vision may vary) :)
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The 275 are supposed to have higher resolution and sharpness vs G5's.
 
How are approaches depicted on the 275 vs G3X?

I assume on the 275 it is similar to what you see on the G5 - with altitude being the small dot on the altitude tape on the HSI.

How is is shown on the G3X?
 
Don't know how helpful this might be but here's the 275 next to the G500 in my plane during the install. Looking at the altitude displays the text seems very similar, if not the same size. Obviously it's a bit more cramped on the 275. The G3X has the same screen resolution as the G500, so I'd imagine it would look similar. inst_cropped.jpg
 
Llewtrah381 said:
Is that an observation or an assumption? I checked out the 275s at OSH and they’re very readable, IMHO, especially compared with existing steam gauges. Actually, more readable than the G5s, I thought.

YVMV (your vision may vary) :)
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Observation. I’ve had a G3X for a few years. I have friends with three airplanes that use dual 275s. The info is there but it’s like comparing my Apple Watch display to my max size iPhone. Or watching hockey on my phone versus a big TV. But my G3X was installed in a new panel in a new airplane. Am I willing to tear out my Cessna’s panel I did 12 years ago to upgrade to a G3X? Nope. I might do two 275s and a 760 (remodeling the panel is easy) but I’m not even thinking about that.
 
Great perspective. How does the 3x depict approaches ? Moving boxes or something else? The G5 altitude dot is not as user friendly for me as the vertical and horizontal bars of the Steam gauge CDI
 
You AP users are over my head. I have a 2 axis AP that runs through my G3X (the exp version doesn't require an controller) but I only use it as a wing leveler to allow me to direct attention to something besides flying for a minute or two. I do enjoy watching videos about the capabilities but it's just for entertainment. My Cub isn't a plane that'll need to do AP approaches. Here's a video by a guy who knows his equipment and does a pretty good job with the narration.

 
WDD said:
How does the 3x depict approaches ? Moving boxes or something else? The G5 altitude dot is not as user friendly for me as the vertical and horizontal bars of the Steam gauge CDI
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HSI bar plus vertical deviation indicator, which is the same as the G1000, which is similar to the GI275 which is similar to the G5.
upload_2022-9-12_19-3-57.png

If you have a GFC500, you can also get "highway-in-the-sky" pathway boxes.

upload_2022-9-12_19-7-6.png

upload_2022-9-12_19-7-29.png
 
Now that is amazing - had no idea.
 
For you G3X folks - is the standard one 10" screen, or does it really need the 10" and 7" combination?
 
Stewartb said:
A mechanic friend is building a panel with two 275s and a 760. Simple and functional. The 275s are too small for my eyes but it’s a nice compromise for a certificated airplane.
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This is a nice option indeed.
 
WDD said:
For you G3X folks - is the standard one 10" screen, or does it really need the 10" and 7" combination?
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Dual 7" and dual 10" are possibilities as well.
 
I use a single 10” and it runs the comm, txp, and AP along with everything else. The exp advantage.
 
Not required for Exp, but I added a GDL39-3D that’s not associated with the G3X for my iPad/iPhone with Garmin Pilot. I asked Garmin about a G5 and the engineer I was talking to said he’d just use GP. The redundant GDL was my security blanket.The only thing lacking is seeing the EIS on an iDevice. The certified guys can, exp guys can’t.
 
With remote comm and txp? I have nothing in the panel but a G3X and switches.
 
MooneyDriver78 said:
Yes, if you have G5 as backup attitude indicator.
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But certified requires a G5 backup AI, so it's not really an "if" case.
Stewartb said:
With remote comm and txp? I have nothing in the panel but a G3X and switches.
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Pretty sure it can remote control comm using SL30 protocol and txp using SL70 protocol, but I don't know of any certified headless comm. The GTX345R is headless and the Grumman Tiger that Garmin uses as their G3x demonstrator has one, so that's proof by example.
 
My RV-14 has a G3X Touch panel, consisting of: 10” PFD, 10” MFD, G5, GTN 650 Xi, autopilot head, dual ADHARS, remote transponder, remote Comm 2, remote audio panel, engine monitor, and 3 autopilot servos. There is a backup battery that powers the PFD, engine monitor, and ADHARS #1. The G5 has its own backup battery. I also have a TOGA button (wired to autopilot head and GTN), a few buttons on the stick, and panel-mounted PTT buttons for when you aren’t flying and want to talk (on the ground, on autopilot, or flying with a copilot). I originally put the EIS strip on the MFD for the first year I flew, but I moved it to the PFD about 6 months ago. I rarely look at the MFD. I use the G5 mostly to input altimeter settings. I use the autopilot head mostly for the knobs (heading and altitude) but I do like having physical buttons for FD, AP, and LVL.

If I were to do it over, I would try to fit in a GTN 750 Xi instead of the 650, remove the MFD, maybe remove the backup ADHARS, and consider a GI 275 instead of the G5. But that’s all. The 10” PFD with EIS strip does everything I need and I rarely look at the MFD. Having a 750 would be a nice form of MFD that would be closer to where I sit.

Copilots like the EFIS Reversion switch that puts a full PFD on their side. Passengers like the big map so they can see traffic, weather, where we are, ETA, and so on. But if you aren’t spending money to appease copilots or passengers, the second G3X screen (in either size) is probably something you’ll end up telling other people is superfluous.
 
Nice POV on the number of screens needed. That really simplifies things.

Is the cost of a G3 7 inch plus GTN 650 is about the same cost as a GTN 750?
 
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WDD said:
Nice POV on the number of screens needed. That really simplifies things.

Is the cost of a G3 7 inch plus GTN 650 is about the same cost as a GTN 750?
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I don’t know the certified-world prices or installation costs. But here are Aircraft Spruce’s experimental-world parts prices:

GTN 750 Xi: $16,670
GTN 650 Xi: $11,671
GDU 460 (10” screen): $4,210
GDU 470 (7” screen): $3,260
GSU 25 (ADHARS): $1,585 (includes full kit so price should be lower for just the GSU)

So a 7” MFD and backup GSU will cost ~$4,500 while the change from 650 to 750 will cost $5,000.

My unrelated certified panel upgrade has me locked into the G500 TXi and GFC 600, so costs are not comparable. But my experience with the G3X Touch in my RV-14 has informed my choices there. Single 10” PFD with EIS strip, GTN 750 Xi, and GTN 650 Xi (which is mostly a Comm #2 in my use but there is no Comm-only radio that integrates as well with the TXi as the GTR 20 in my RV-14 integrates with the G3X Touch, and that integration is worth it to me).
 
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