Garmin G5 to GNX175 wiring question

Dave Anderson

Dave Anderson

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I’m purchasing a Bristell w Nav/Com and dual G3X. It has ads-b in/out

it previously had a G5 installed but the owner removed it. I wouldn’t mind adding a GPS-175 but curious wha the install might require. There is a blanked space plenty big above the nav/com and audio panel. Is some of that wiring from the G5 plug and play? I’m asking as I want to do some ifr training.
 
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Plug and play? Uh, no. It's not particularly difficult, but you'll be building the harness with the correct pinouts for your application You'll have to wire RS-232 and probably ARINC. You may need a GAD29, I'm not sure with your install. You will have to know what you are doing. It isn't difficult to figure out, but certainly not "plug and play".
 
Salty said:
I assumed he meant GPS175
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Yeah, but could be a GNX375. Or could be a GI275 since a backup EFIS to replace the missing G5 is needed to make the G3x IFR.
 
asicer said:
Yeah, but could be a GNX375. Or could be a GI275 since a backup EFIS to replace the missing G5 is needed to make the G3x IFR.
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A GI275 wouldn't make it IFR, you'd need a GPS capable of approaches. Why would you get a GNX375 when you already have ADSB in/out, so doubt that also.

*edit* technically my first sentence is wrong, since the plane has a nav/comm, but I still doubt it.
 
Salty said:
A GI275 wouldn't make it IFR, you'd need a GPS capable of approaches.
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A GI275 alone won't make it IFR, but you still need a backup to replace the removed G5. There was no mention of a GPS navigator in post #1, so that's another bit of ambiguity. But yeah, if that's not there then that's a second piece that's needed for GPS approaches.
 
Salty said:
Plug and play? Uh, no. It's not particularly difficult, but you'll be building the harness with the correct pinouts for your application You'll have to wire RS-232 and probably ARINC. You may need a GAD29, I'm not sure with your install. You will have to know what you are doing. It isn't difficult to figure out, but certainly not "plug and play".
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Thanks, just wasn't sure if some of the wiring was similar since the G5 was In previously.
 
Dave Anderson said:
Thanks, just wasn't sure if some of the wiring was similar since the G5 was In previously.
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Popping a G5 back in might be trivial. Maybe. But adding a 175 will not be.
 
Actually, as IFR GPS unit installations go, a 175 is pretty stinkin' easy.
 
Thanks All. VFR pilot wanting to do IFR training, trying to decide if worth the cost since can't do IFR in LSA. Sure seems to be a nice safety feature (at least that is what i'm telling my wife)
 
So then the question, is the GPS 175 worth it? I have a NAV/COM and spare radio. Dual G3X ADS-B IN/OUT I probably won't go full IFR but want to do some training until I decide if I want to upgrade and go full PPL/IFR
 
Also Consider replacing the second radio with a gnc-355
 
Dave Anderson said:
Instead of? I'll admit I know next to nothing about this.

The GPS-175 is about $4500 and the GNC 550 is $6500. What is the advantage
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Instead of installing a GPS-175. The GNC-355 is a GPS-175 + Comm radio. Might not be worth it if you are happy with your existing radios. The biggest benefit is the ability to select frequencies easily from the gps data. Probably not worth the extra $2k unless space is an issue.
 
Salty said:
Instead of installing a GPS-175. The GNC-355 is a GPS-175 + Comm radio. Might not be worth it if you are happy with your existing radios. The biggest benefit is the ability to select frequencies easily from the gps data. Probably not worth the extra $2k unless space is an issue.
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So much to learn. I know the GnX-375 is Navigator w Adb-B/In/out but 8k

Either might be overkill at the movement but trying to understand my options. The plane is undergoing an annual before I take possession just deciding what is worth it.

It has a GNC-255A in it now, unless the used value in that is enough?

Space isn't an issue.
 
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How many COM radios do you currently have and how many NAV radios?
 
Dave Anderson said:
One Remote COM for the G3X and one GNC-255A COM/NAV
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If you already have 2 good COM radios then you definitely do not want a GNC355, unless for some strange reason your audio panel is capable of 3 COM and you feel some weird need for 3 COM.

You say you have both ADS-B Out and ADS-B In. However, you don't say how you are doing it. If it is via a GTX345 transponder, then you should be able to see TIS-B (traffic) and FIS-B (weather) on your G3x. In that case, you can rule out the GNX375 since aside from IFR GPS navigation it doesn't do anything you aren't already doing. However, if it's via a Stratus ESGi or SkyBeacon/TailBeacon then you're probably getting FIS-B/TIS-B on your tablet rather than the G3x. If it's a Lynx NGT-9000 then you might getting FIS-B/TIS-B on its screen rather than the G3x. A GNX375 might be worth the expense since it would allow you to see all that info on the G3x rather than yet another device, which would especially be nice since traffic would show up as a growing yellow dot on the artificial horizon and/or synthetic vision instead of having to look down at an inset or switch to the traffic circle page.

So if you rule out the GNC355 and the GNX375, that leaves the GPS175 if all you want to do is add IFR GPS navigation. However, you might feel the need for a 2nd NAV radio. Some people do, some don't. It is certainly possible to train for IFR without it, though. If you do want a 2nd NAV radio, then you'll want to look at a GTN650xi or GTN750xi. However, going that route would mean removing your remote COM radio. And if you don't already have a GTX345 transponder then a GTN won't give you traffic and weather on your G3x like a GNX375 would.
 
asicer said:
If you already have 2 good COM radios then you definitely do not want a GNC355, unless for some strange reason your audio panel is capable of 3 COM and you feel some weird need for 3 COM.

You say you have both ADS-B Out and ADS-B In. However, you don't say how you are doing it. If it is via a GTX345 transponder, then you should be able to see TIS-B (traffic) and FIS-B (weather) on your G3x. In that case, you can rule out the GNX375 since aside from IFR GPS navigation it doesn't do anything you aren't already doing. However, if it's via a Stratus ESGi or SkyBeacon/TailBeacon then you're probably getting FIS-B/TIS-B on your tablet rather than the G3x. If it's a Lynx NGT-9000 then you might getting FIS-B/TIS-B on its screen rather than the G3x. A GNX375 might be worth the expense since it would allow you to see all that info on the G3x rather than yet another device, which would especially be nice since traffic would show up as a growing yellow dot on the artificial horizon and/or synthetic vision instead of having to look down at an inset or switch to the traffic circle page.

So if you rule out the GNC355 and the GNX375, that leaves the GPS175 if all you want to do is add IFR GPS navigation. However, you might feel the need for a 2nd NAV radio. Some people do, some don't. It is certainly possible to train for IFR without it, though. If you do want a 2nd NAV radio, then you'll want to look at a GTN650xi or GTN750xi. However, going that route would mean removing your remote COM radio. And if you don't already have a GTX345 transponder then a GTN won't give you traffic and weather on your G3x like a GNX375 would.
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ADS-B in IS with a GDL-39R

I also have a mini-sentry on my iPad.

The other com is a 20R
 
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asicer said:
Cool. So that rules out the GNC355 and GNX375. That just leave the GPS175 or one of the GTN.
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Yes, unless I traded something to combine functions but I don't see value in that approach. The GP's-175 seemed to be the most cost effective solution.
I'm not an IFR pilot just want to learn and Build some time.
 
Dave Anderson said:
Yes, unless I traded something to combine functions but I don't see value in that approach.
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You might be able to shave some weight by combining functions. But yes, you are correct in that it's a lot of work and money for just a few pounds.
 
asicer said:
You might be able to shave some weight by combining functions. But yes, you are correct in that it's a lot of work and money for just a few pounds.
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Every lb is a pair of shoes my wife can pack.

What is the smart combo for the $ if that was an option?

The GNX 375 would replace the GDL-39 and the remote transponder and add WAAS

Too many options and decisions and not enough $
 
If your wife is packing shoes, that means you're traveling. If you're traveling, the instrument ticket is your best investment. Get the 175 and spend the balance on the ticket.
 
Dave Anderson said:
Every lb is a pair of shoes my wife can pack.

What is the smart combo for the $ if that was an option?

The GNX 375 would replace the GDL-39 and the remote transponder and add WAAS

Too many options and decisions and not enough $
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I don't have the GTR20 installation manual, so you'll need to Google around for the weight of that unit. Keep in mind that the GNC355/GNX375 have a couple of pounds over the GPS175 so you'll need to factor that back in to whatever you take out.
 
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