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Question for Garmin Expert

Tankerpilot75

Well Known Member
I’m considering purchasing the Garmin GNC 355 to replace one of my two non-WAAS 430s. I would like to have a WAAS navigator with comm but don’t want to pay the price of a new 650. Used 430w gps’ are too expensive for an older navigator and are getting long in the tooth. However I do want the capability of flying the occasional VOR or ILS approach - which I should be able to do with my remaining 430.

I’m also planning to upgrade my old Horizon WS EFIS units to GRT’s Horizon EX units.

Here are my questions:
1. Using an ARINC module can I install a gps “selection switch” to send either 355 or 430 gps data to my EFIS units? Example: switch up = 355; switch down = 430.

2. Since the 355 does not support VOR/LOC can I use one EFIS serial port for vertical guidance for the 355 and another serial port for VOR/ILS guidance from the 430 on the EFIS unit.

3. Is there some better alternative to allow both the 355 and 430 to provide the total capabilities I want?
 
The source switching is up to how your EFIS handles it's ARINC inputs. It should be able to receive multiple sources but you should check with GRT on that.
 
I’d ask, what gps capabilities do you want from the 430? Here’s what I’d suggest:
1. From the 355, run an arinc-out pair to one of the arinc-in pair inputs on the GRT arinc module.
2. From the 355, run an rs232-out line to an EX rs232-in port, format it gps1.
3.from the 430, run a pair of wires from the vor/ils arinc-out pair, to the other arinc-in pair on the grt arinc module.
4. From the 430, connect 2 rs232 lines (in and out) to in and out rs232 ports on the EX. Format them gps2.
5. From the EX arinc module, there is one arinc out port. Splice four wires into two, connect them to the EX arinc-out. Run one pair to the 355 arinc in, the other pair to the 430 arinc in.
In normal use you’ll choose gps 1. This will drive the EXs internal navigation, maps, etc. It will also drive LPV, Garmin’s LNAV+V, and LNAV approaches from the 355. Of course if you choose NAV on the EX you’ll be using the vor/ILS from the 430. I don’t think gps approach data will come thru to the EX from the 430 gps. You could get it by, as you suggested, putting in a dpdt switch to switch the arinc pair into the ex between the 355 and 430 (gps side). But once you get used to LPV and LNAV+V approaches you’ll never use it. In case of a 355 failure you can switch to gps2 in the efis and use the 430 for the moving map. And it’s not hard to shoot an LNAV using either the 430’s moving map, or the cdi on page 1 of the 430.
 
I think Bob has it correct.

Like you, I have been pondering upgrading my GRT/GNS430 panel. I have finally decided to replace my non WAAS GNS430 with a GNC355. I'm keeping my older 2 screens GRT Sport EFIS. I have been using the Garmin GNC 355 simulator on my iPad and it's very useful, especially having the reference materials included. But yesterday I used it with the 1 hour GTN course on YouTube to do the flight from KAPA to KCOS. Wow! The features of the new navigators are impressive!

I looked at going with a GPS175 and GTR200 com to save a little money, but I don't have the panel space and the integration of the com with the gps in the GNC355 is very good.

I'd suggest you try the YouTube videos to get an idea of how the GNC will operate, its mostly the same as a GTN. You can find them at:
https://www.youtube.com/playlist?list=PLF9A599F75408E57F

Now I'm starting to wonder where I want to locate the GNC355. My GRT screens are side by side and as high up as possible. My GNS430 is below the right side screen. But as graphic as the GNC355 is, I wonder if I want it above the right side GRT. The install will be easier if I place it where the GNS430 is and since I use the GRT map while enroute to display traffic and weather, keeping it at the top probably makes the most sense.

I hope this is helpful.

Jim Butcher
 
G300 question for the Garmin Expert

The G300 in SkyCatcher I use for instruction has a configuration module issue - it doesn't remember the last Tach or Hobbs times between flights. :mad:

It shows a Configuration Module not found message - no surprise.

The question is: where is the Configuration module, and can it be replaced?
Our mechanic has queried his Cessna contacts, but no response so far.

Any suggestions?
 
It's inside one of the connectors going into the G300. You can most likely replace it with a regular garmin config module. Call a nearby large avionics shop and they will likely just give you one for free, they come with just about every darned thing you buy from Garmin ;-D
 
Jim, don't forget that the GNC 355 does not include an intercom, so you have to get an audio panel or similar to compensate for this.

This is what ultimately made me rule out the 355 as an option. If I have to take up panel space for the audio panel, may as well just get the GPS 175 + GTR 200B. Comes out cheaper too.
 
Jim, don't forget that the GNC 355 does not include an intercom, so you have to get an audio panel or similar to compensate for this.

This is what ultimately made me rule out the 355 as an option. If I have to take up panel space for the audio panel, may as well just get the GPS 175 + GTR 200B. Comes out cheaper too.

No problem. I already have the Garmin 340 in my panel. Right now I’m waiting on delivery of my two new GRT Horizon EX units and a new ARINC 429 module. One these units are installed I’ll get serious about the GNC 355.

I’ve had several folks contact me wanting to sell me their “used” 430W units for $5,500 and above. Frankly, the used 430W market is way, way overpriced IMHO!
 
49clipper

Can anyone give me a good phone number for the garmin G3X experimental experts? I have several issues on my new system. Mostly now on the AP.
Jim
 
Jim, don't forget that the GNC 355 does not include an intercom, so you have to get an audio panel or similar to compensate for this.

This is what ultimately made me rule out the 355 as an option. If I have to take up panel space for the audio panel, may as well just get the GPS 175 + GTR 200B. Comes out cheaper too.

I installed a GNC355 and used a PDA360 XR remote audio panel/intercom, all plugged into my dual AFS5600T's
 
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