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GPS175

Amadeus

Well Known Member
My -12iS has the dual G3X avionics and I wish to add GPS175 for IFR capability. Has anyone done this already who can advise me on the level of difficulty of adding this myself?

Sidebar: There is quite the debate about the regulations around IMC in a LSA that I am happy to discuss elsewhere but I'm curious right now about whether the installation should be left to a professional or whether I could tackle this myself.
 
Okay, sidestepping the question of LSA vs EAB, and also sidestepping the question of how many backups are enough for actual operation in IMC:
There are many EAB builders who have built their own panels. It’s just one wire at a time. Use good crimpers.
 
My -12iS has the dual G3X avionics and I wish to add GPS175 for IFR capability. Has anyone done this already who can advise me on the level of difficulty of adding this myself?

Sidebar: There is quite the debate about the regulations around IMC in a LSA that I am happy to discuss elsewhere but I'm curious right now about whether the installation should be left to a professional or whether I could tackle this myself.

Also curious how difficult this is to manage for the average builder.
 
Is it build as an EAB?

E-LSA already flying.

Which is why I'm unsure of the difficulty of changing things at this point. I know it will include removal and replacing a new center section of the panel but do the ports exist to add a navigation unit after the fact?
 
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Assuming the 175 has similar connectors to the 375 they use high density connectors versus the "typical" DB9/25/37 connectors and there is also a configuration module that is part of the connector. While I built my own panel and have the various crimpers etc. I decided to have Stein build the cable for the navigator end and leave sufficient length for me to hook up the other components. Worked well and Stein also provided a drawing with the requested pinout connections etc.
Figs
 
When I bought my GPS175 from ACS, the only way I could buy the experimental version of it was if I also bought the wiring harness. The certified version must be installed by an avionics shop. The wiring harness made it pretty easy to install since I didn't have to deal with the one end of the connection. I wouldn't suggest that someone who hasn't done any avionics wiring start with this vital of an installation, but it's well in the grasp of someone with a bit of experience.
 
I had a conversation with someone at Stein about this, but in the context of a Dynon setup.

If you're capable of doing the panel modification to mount the unit, I'm sure you could buy the GPS-175 with a custom wiring harness from Stein. They make the harness for the RV-12, so they know exactly what's needed (assuming you haven't already modified things).
 
I could be wrong, but do not think you can put a GPS-175 in an E-LSA. You could do the 650 I would guess as that is an option with them, but isnt that modifying the airplane outside the builders spec?

E-LSA already flying.

Which is why I'm unsure of the difficulty of changing things at this point. I know it will include removal and replacing a new center section of the panel but do the ports exist to add a navigation unit after the fact?
 
I could be wrong, but do not think you can put a GPS-175 in an E-LSA. You could do the 650 I would guess as that is an option with them, but isnt that modifying the airplane outside the builders spec?

It's an E-LSA. As soon as you have the airworthiness certificate that confims you BUILT it per the spec, you can modify it as you wish.
 
GPS 175 Installation

My -12iS has the dual G3X avionics and I wish to add GPS175 for IFR capability. Has anyone done this already who can advise me on the level of difficulty of adding this myself?

Sidebar: There is quite the debate about the regulations around IMC in a LSA that I am happy to discuss elsewhere but I'm curious right now about whether the installation should be left to a professional or whether I could tackle this myself.

We can only offer so much guidance on the physical installation of the unit itself in the instrument panel, but we are happy to assist in the wiring and configuration that would be required to power the unit and interface it to your G3X Touch system. Please feel free to reach out to us via email at [email protected] or via phone at the number listed in our signature.

Thanks,

Justin
 
I haven't installed the GPS175, but I did look through the installation manual.

I think the challenge is to make your own mounting brackets to secure the tray properly.

The pin-outs/connections to other components that you have seem pretty straightforward.. easier than a GTN650 for sure. Once you write up your wiring diagram..should be fairly easy.

If you do fly in IMC, I'd recommend a second AHRS unit for the G3X too, as they aren't toooo expensive.
 
If you're capable of doing the panel modification to mount the unit, I'm sure you could buy the GPS-175 with a custom wiring harness from Stein. They make the harness for the RV-12, so they know exactly what's needed (assuming you haven't already modified things).

I installed a GPS175 in my RV-12 earlier this year (E-LSA which was flying for many years). Agree with Joe above, just contact Stein (or other reputable supplier) and have them build the wiring harness to properly talk to Dynon. Stein knows the RV-12 wiring inside and out, so I'd recommend them. Its simply plug in, some minor software configurations, and it works. Seemless with the Skyview BTW.

One issue I am concerned with is antenna placement on the RV-12. I went the most simple route and added it on the shelf over the engine, under the cowl. That shelf is lower than the top of the firewall of course. After several months of experience now, I'm occasionally getting loss of GPS satellite integrity. It comes back in a few seconds. Seems more frequent in turbulent flight, which I suspect is partly due to some firewall caused sky blockage. I'm pretty much decided to move the antenna to the top of the tailcone which will require a longer coax cable which I'll snake down the center channel. It likely requires removal of the fuel tank to get back there, (if only I did it when completing the tailcone SB earlier in the year!)
 
If you do fly in IMC, I'd recommend a second AHRS unit for the G3X too, as they aren't toooo expensive.

That' exactly what a G5 is for. In the case the main GSU AHRS LRU goes down the G3X system will link up to the G5 internal ADAHRS and keep on trucking. Days of dual GSUs kind of went away with the advent of the G5.

If you don't have a G5 then yes, second GSU. Not even the GI 275 can step in as a G3X ADAHRS source. Only the G5 can. Which is why the G5 is always the preferred backup instrument for a G3X system.
 
What about the Levil BOM?

I have a Levil BOM sitting on the shelf - we tested it in a number of airplanes, and its works….but only when it can keep its connection to an iPad, which is rarely. I’d say we could get too to work about 50%of the time, and that was when we dedicated all of our attention to it. Definitely NOT reliable in any respect as a backup….to anything….
 
I have a iLevel 3 as a backup. I found the attitude indication lags quite a bit. The Stratus 3 is really good, and if in IMC AI would trust it as a backup.
 
Dynon D3 Pocket Panel

Installed one of these as a backup. Battery powered, has proven to be reliable & under $900.
 
I have a iLevel 3 as a backup. I found the attitude indication lags quite a bit. The Stratus 3 is really good, and if in IMC AI would trust it as a backup.

I still have my Stratus 2 used in my flying club days before getting the RV smile. It was always accurate connected to ForeFlight so maybe get a Ram mount for the iPad and use that set-up when potentially going to see some IMC.

Heavy IMC is not my intent with the GPS175. We get some morning fog here that sometimes doesn't burn off until close to lunchtime that has kept me sitting and waiting - all the while knowing that just 200' to 300' AGL is clear sky!

The reverse is also true. Many afternoons we will have a layer of cloud at 4,000' move in and I would prefer to fly above that coming back home (avoiding turbulence at 3,000') then drop through on an RNAV approach.
 
While I built my own panel and have the various crimpers etc. I decided to have Stein build the cable for the navigator end and leave sufficient length for me to hook up the other components. Worked well and Stein also provided a drawing with the requested pinout connections etc.
Figs

Nick at Stein said that they can do the cables and drawings for all Van's models other than the RV-12iS. He claims that Van's did some proprietary cabling so that nothing that didn't come with the Van's ELSA avionics package could be added to it.

I'm skeptical to say the least. These are GARMIN avionics. Garmin isn't going to change the inputs/outputs on their hardware for a handful of the G3X market that the RV-12iS represents.

Contacting g3xpert for guidance.
 
Same for Dynon or only Garmin

Nick at Stein said that they can do the cables and drawings for all Van's models other than the RV-12iS. He claims that Van's did some proprietary cabling so that nothing that didn't come with the Van's ELSA avionics package could be added to it.

I'm skeptical to say the least. These are GARMIN avionics. Garmin isn't going to change the inputs/outputs on their hardware for a handful of the G3X market that the RV-12iS represents.

Contacting g3xpert for guidance.

Jayson, Did Nick say this applies to both Garmin and Dynon avionics that Vans offers?

Thanks,

Steve

PP/LSRM-I
'22 Donation made
2020 RV-12iS Dynon 120482
TBD RV-8A 81635
 
Jayson, Did Nick say this applies to both Garmin and Dynon avionics that Vans offers?

I did not inquire about Dynon. But I cannot believe it would be true about either. Stein provides avionics packages to Van's and perhaps it is more of a "gentleman's agreement" to not change the options on E-LSA RV-12s but why not provide additional avionics AFTER airworthy?
 
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One issue I am concerned with is antenna placement on the RV-12. I went the most simple route and added it on the shelf over the engine, under the cowl. That shelf is lower than the top of the firewall of course. After several months of experience now, I'm occasionally getting loss of GPS satellite integrity. It comes back in a few seconds.

I finally got around to relocating the GPS175 antenna from where I had originally installed it (under cowl, on shelf beside the Dynon ADSB-antenna) to the topside of the forward tail cone. After some long flights, it was clear that the under cowl location would regularly lead the Garmin unit to "reset", drop all the satellites and begin to require them. Process would take 10-15 seconds and if I was on an approach I would be required to go missed. Not acceptable.








Below is a shot of what the satellite reception was when the antenna was below the cowl. Again, it worked "most" of the time, but would lose adequate satellite coverage periodically.



Below is just the initially start up with the aircraft sitting on the taxiway between two hanger rows, so it was not in a normal flight condition. Already it is clear that the more exposed location is substantially better. I've conducted one short test flight and so far not a single failure. A little touchup paint and I'm done.

For anyone considering the addition of a WAAS GPS unit for the 12, while the undercowl location for the antenna might be attractive, its just not reliable for consistent reception.

 
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