Avionics question

[Kitfox Pilot]

Remember I know nothing much on this subject and am laying out my garmin supplies in the plane.
I need aft weigh and my question is what items should I not put in the back, behind the seat area, of the plane?
Below is the list of items to mount.
Autopilot servos are all ready in and the gmu 11 is out in the wing and g3x and 507 are on the panel.
Battery is going behind the baggage compartment and I'd like to mount the vp-x behind the seat??


Left to mount is gsu 25, gtr20 remote com radio, gdl 50 adsb in, gea 24 engine monitor. Any of these need to be up front?


I'm not mounting a transponder or adsb out at this time. Thanks

[Delta Whisky]

Harlan - I don't know any specifics about the GEA 24 but if thermocouple wires go direct to it, you probably would be better off keeping it closer to the firewall then behind the seats. Maybe a Garmin guy will weigh in.

[jiott]

If you have not yet decided on engine/prop, I don't see how you can possibly decide where to mount the items you mentioned for proper cg location. Maybe I missed it and you have settled on engine/prop?

[Kitfox Pilot]

915 engine , airmaster prop.

[efwd]

Keep the GEA 24 up front. It doesn't weight anything, so no significant penalty there. The GSU 25 has mounting holes right in the back of the G3X if you want. Downfall to that is you have to run pitot tube hose all the way to the firewall and up to the back of the panel. Just gets crowded that's all.

[PapuaPilot]

I have a G3X and would recommend mounting the GEA-24 between the firewall and instrument panel. It is the unit that all the sensors & inputs are connected to and it only weighs 1.6#. If you put it into the tail then you have to run all of your engine sensor wiring to the tail, which adds uneeded weight.

The only other things (other than the A/P servos) that you can put in the tail would be the GTR-20 remote COM, the GDL-50 ADSB and GA-35 antenna. I put my GSU-25 in the tail to keep the static port runs to a minimum.

I don't see a transponder on your list. Are you planning on one and ADSB-In? There are remote transponders that could be mounted in the tail, which can be controlled by the G3X.

Also, the ELT can be mounted in the tail.

[Kitfox Pilot]

Phil, I'm not putting a transponder or adsb out in at this time. Planning on putting the elt on the elt mount because I assume I need to reach it.

Eddie, do you think the vp-x is ok behind the seat?

Thanks Guys.

[Shadowrider]

Harlan,

Seems like there is always something you don't think about and I am trying to think of issues you may have. One is you may have to get creative to get all your wiring tucked away neatly. Also you may want to try and keep power away from the ELT as much as possible. I know some have had problems with the ELT inadvertently going off? Not sure if the exact cause was found, but I think they are thinking you don't want power running close to the ELT remote wires. Maybe you are going to run the artex instead of the ACK. Doing it again I think I would switch. Wondering if it would be worth moving VPX to the back because you have more wiring to run and its not that heavy? Of course power to the avionics that are remote mounted is a shortened distance, but you do have a longer distance for the ground and power supplies to the VPX. Just thinking out lot. I have sometimes wondered if moving the header tank and enlarging it would be a good option for others going 915. I know your covered so it not something you want to do.

[avidflyer]

As much as a guy hates to think about adding weight to the tail, this is something to consider as well. 2 lbs of weight at the tailwheel equal about 10 lbs of weight just behind the seat for CG purposes. Maybe it comes down to adding a heavier tailwheel and you save a bunch of other issues that may complicate the build. Not saying this is the way to go, but putting it out there as something else to consider. JImChuk

[Shadowrider]

Thanks Jimchuk. Basically that is what I was trying to say. Maybe easier to just add weight to the tail!