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Remote Avionics Mounting Ideas/Pictures

iamtheari

Well Known Member
I am doing a Garmin G3X Touch system in my RV-14, with the higher end of average number of remote avionics. The sub panel provides some space to work with and I know that most people seem to build rails to connect the panel and sub panel lower flanges to gain some more real estate. But I think I'll still come up short.

I need to mount the following items remotely:
* VP-X
* IBBS backup battery
* GD-40 CO detector
* GEA 24 engine monitor
* GAD 29 ARINC 429 interface
* GSU 25 primary ADAHRS (the secondary one can live on the back of the MFD but I think it's preferable to have the primary mounted directly to the airframe)
* GMA 245R audio panel
* GTR 20 comm radio
* GTX 45R transponder, in mounting tray

I will have a GTN 650 and GMC 507 in the center stack of the panel. That may leave some room for the audio panel, comm radio, and/or transponder to be mounted in the center stack but offset behind the panel. Has anyone done that or had thoughts against it?

I know that some people put the transponder on the battery angles in the tailcone, between the baggage bulkhead and the bell crank. Does anyone have pictures of this installation? It makes sense because it will shorten the length of transponder antenna cabling, although I think Garmin wants a certain minimum length so that may not be an advantage. I have a couple of extra nut plates on those battery angles (installed in the extra locations used in the RV-10 as called out in the RV-14 plans) because I was going to put my smoke oil pump there, but I ended up mounting that on the side of the tank to make plumbing easier. I'm not sure if those will be a help or a hindrance to putting the transponder tray there.

I'm thinking about putting the GEA 24 on the forward side of the sub panel since most of its wires go to the firewall. Has anyone done that? I know it won't be easy to work on it because I'll have to lie on my back under the panel, but it seems to me that any work I have to do on the engine monitor connections will be tedious regardless of where the GEA 24 gets mounted.

I can probably put the GSU 25, GAD 29, and maybe GD-40 on the aft side of the left sub panel, the IBBS in the vicinity of the map box cutout on the right side, the VP-X on rails on the right side, and have room for maybe one big box on rails on the left side if needed (transponder, comm radio, or audio panel).

All ideas, stories, and pictures are welcome. I am ready to build my wiring harness as soon as I figure out where all the connectors will need to end up. Thanks, everyone!
 
I mounted all my stuff (similar list to yours less the VPX) using drop-down tray/shelves behind the PFD/MFD, on the sub-panel, and behind the glovebox opening. Took a bit of trial and error and fashioning some "stacked" trays to fit everything, while avoiding interference with panel mounted items.

(see blog posts starting on this page: https://turnerb14a.blogspot.com/2018/11/working-on-avionics.html)

As far as center stack goes, I went with panel mount audio panel as I really like the manual controls for panel functions.

If I were building again, I'd leave the forward skin off until avionics were installed. Would have been easier (but harder to reach those rivets!).
 
I mounted all my stuff (similar list to yours less the VPX) using drop-down tray/shelves behind the PFD/MFD, on the sub-panel, and behind the glovebox opening. Took a bit of trial and error and fashioning some "stacked" trays to fit everything, while avoiding interference with panel mounted items.

(see blog posts starting on this page: https://turnerb14a.blogspot.com/2018/11/working-on-avionics.html)

As far as center stack goes, I went with panel mount audio panel as I really like the manual controls for panel functions.

If I were building again, I'd leave the forward skin off until avionics were installed. Would have been easier (but harder to reach those rivets!).
Your blog and a few others' have been receiving steady traffic from my work IP address for the past month. Thank you for documenting what you did. You really did stack things up on that drop-down tray. It looks like you have the IBBS, transponder, and GD-40 all on it. Is it stable enough in flight or do you wish you had used angle material on the edges to stiffen it up? (I'm guessing that the transponder mounting tray lends some stability to the structure.)

I am sure that there will be times when I wish I had the audio panel physical buttons in my panel, but I decided that ultimately my flying habits don't require it. I'll have access to much of that on my stick, thanks to Garmin's plentiful discrete inputs. (The only one that I wish they had but they still don't is a remote 'pause' button for Bluetooth audio. I just can't stand ATC talking over the top of my audiobooks!)

The forward skin was a really tough decision for me. I decided to rivet mine on to make sure I had maximum strength and stability at the final shape when I did the canopy.
 
Your blog and a few others' have been receiving steady traffic from my work IP address for the past month. Thank you for documenting what you did. You really did stack things up on that drop-down tray. It looks like you have the IBBS, transponder, and GD-40 all on it. Is it stable enough in flight or do you wish you had used angle material on the edges to stiffen it up? (I'm guessing that the transponder mounting tray lends some stability to the structure.)

I am sure that there will be times when I wish I had the audio panel physical buttons in my panel, but I decided that ultimately my flying habits don't require it. I'll have access to much of that on my stick, thanks to Garmin's plentiful discrete inputs. (The only one that I wish they had but they still don't is a remote 'pause' button for Bluetooth audio. I just can't stand ATC talking over the top of my audiobooks!)

The forward skin was a really tough decision for me. I decided to rivet mine on to make sure I had maximum strength and stability at the final shape when I did the canopy.

No issues at all with the trays. What you don't see in blog is that I riveted stiffeners (1/2" x 1/8" aluminum) to the bottom of each one.
 
I have a similar list with the exception of VPX.
Most have been mounted on the subpanel, vertically. The remote radio and TXPR has been mounted right behind the baggage area on what is a battery support bracket for RV10 which is not used in a 14.

All very easily accessible.

I will be happy to send a picture if you like or I believe I have provided some pictures in the RV14 completed section.
 
I am still playing with ideas on this. Thanks to everyone who has sent me pictures and thoughts!

One idea I have is to mount the VP-X underneath the forward top skin, between the F-01456 forward fuselage ribs. Those ribs have a bottom flange and I could attach two lengths of aluminum angle, cross-wise, to that flange using nutplates. That would give me two rails that I could attach the VP-X mounting brackets to.

That location would be well out of the way of everything I can think of, since the rudder pedal mounting blocks and both firewall penetrations for wiring and control cables are all lower than those ribs. There should not be any interference with the airframe or the occupants. The wiring would not be super-fun to reach but this is a unit not likely to go in and out very often.

The VP-X Pro specifications say that it weighs 2.1 lb, not including the mounting brackets or electrical connectors. That keeps its weight under 25 lb up to 12G, at which point I would probably be more worried about regaining consciousness and bailing out of a broken airplane than a loose VP-X flopping around in the plane.

Has anyone considered this mounting location for anything and then either used it or rejected it? I'm hoping to get some input on this one before I start drilling. :)
 
A48-D2198-1201-4357-A296-DA908-E926-FC5.jpg
 
Did you have any interference issues with the gmu22 near the pitch and yaw servo? Did you put it on the roof?

Did you put your transponder antenna in the aft bottom skin location?
 
There are lots of threads on all this.

I put my transponder and remote radio in a bracket thru the map box hole.

There is plenty of room on the sub panel for the GEA24, GAS29 and others. If you mount on both fwd and aft sides of the sub panel watch out for the canopy struts. I put nutplates on the forward side so I can remove the boxen simply without having to hold a nut on the back. I didn't put any boxes on the forward side of the sub panel for maintenance reasons.

You shouldn't put the transponder cable all the way aft; that was for ADSB "in"; the transponder/ADSB "out" goes best under the right baggage compartment. I have tape over that hole at the moment might put a 2m ham rig in one day.

The GMU22 works fine in the left wing shelf.

Definitely don't install the forward top skin until all the avionics is in; it is a drag to rivet around things but more of a drag to route wiring blind.
 
GTX45

Realize that the GTX45R has bluetooth connectivity; it therefore has an antenna. According to Garmin, that antenna is somewhat directional, and is located behind the Garmin sticker on the unit.

That sticker is on the opposite end of the unit from the antenna connection. Be aware that if you mount it aft, you will need to loop the cabling around the rear of the unit so the BT antenna is pointed forward...and...if there is a metal bulkhead between the antenna and the cabin area, you can expect degraded to no BT connectivity.

Also, and this is important, your diagram shows the boxes but you MUST also figure for the connectors, some of which will require another 3-4 inches of space...

I am working on this in my -10 build right now. I have basically the same equipment and it was a challenge to get it all to fit and not block any of the connectors. Also realize that there are a TON of wires and the bundles are not small...

Good luck!
 
There are lots of threads on all this.

I put my transponder and remote radio in a bracket thru the map box hole.

There is plenty of room on the sub panel for the GEA24, GAS29 and others. If you mount on both fwd and aft sides of the sub panel watch out for the canopy struts. I put nutplates on the forward side so I can remove the boxen simply without having to hold a nut on the back. I didn't put any boxes on the forward side of the sub panel for maintenance reasons.

You shouldn't put the transponder cable all the way aft; that was for ADSB "in"; the transponder/ADSB "out" goes best under the right baggage compartment. I have tape over that hole at the moment might put a 2m ham rig in one day.

The GMU22 works fine in the left wing shelf.

Definitely don't install the forward top skin until all the avionics is in; it is a drag to rivet around things but more of a drag to route wiring blind.
Do you have a picture of your bracket in the map box hole? It seems to me that it would be a difficult place to stabilize even one device, much less two. But using that space would really free up a lot of space elsewhere.
 
Another option

One solution, which lucky for me was done automatically for by Aerotronics was to build a tray that mounts to the panel on the outside of your screens to mount all your boxes too. With my panel, the only things I had to mount was the remote transponder and the backup battery.

IMG_0664.HEIC



IMG_0665.HEIC
 
One solution, which lucky for me was done automatically for by Aerotronics was to build a tray that mounts to the panel on the outside of your screens to mount all your boxes too. With my panel, the only things I had to mount was the remote transponder and the backup battery.

IMG_0664.HEIC



IMG_0665.HEIC

Rob,

Where did you mount your remote transponder and back up battery? Do you have any pictures. I also had my panel done by Aerotronics.
 
Dynon/AFS

Here are a couple of shots of my recent Dynon/AFS install. Not exactly apples to apples but it does show the general arrangement of common components. Hope this helps.
 

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Rob,

Where did you mount your remote transponder and back up battery? Do you have any pictures. I also had my panel done by Aerotronics.

I mounted the transponder on a tray I built that hinges off the firewall and screws into the angle bracket at the map box. The IBBS is mounted vertically on the backside on the panel (just forward of the pfd).
 
I'll try to post some pictures of what I ended up doing to help close the loop on this thread. I would do that now but it's too much of a mess with my point-to-point wiring about 1/3 done. But for now I will just try to describe my solution:

I mounted my IBBS to the sub panel, upper left corner. I mounted both GSU 25's to the sub panel inboard of that, one above the other.

I used some heavy aluminum (can't remember thickness offhand) to make two trays. One is mounted with four screws and nuts (I was going to use nut plates but this was just easier) to the flanges on the bottom of the panel and sub panel on the pilot side, and the other is mounted the same way on the copilot side.

The pilot side tray has the GTR 20 radio mounted on top and the GMA 245R audio panel mounted on the bottom, which gives me access to the USB charging port on the front of it. The copilot side tray has the GAD 29 bolted to the top inboard side, my GD-40 CO detector bolted to the bottom side, and then two risers made out of sheet metal to mount the GTX 45R tray. The transponder can slide in and out of its tray over the canopy rail.

I used two long pieces of angle aluminum to make a tray for the VP-X, which I then attached with screws and nuts to the flanges on the bottom of the sub panel-to-firewall ribs. A little extra material sticks out the pilot side, where I mounted the GEA 24.

I haven't finished wiring everything yet, but I am happy with the results so far.

One thing I wish I had thought of long ago, when I was first working on the firewall: We drilled out the nut plate below the MAP sensor mount, which is not used in the Garmin install. Then we attached a grounding tab block to the aft side of that and bolted the battery negative cable to the forward side.
 
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