Before actual, after plan. After sleeping on it, radio and transponder will move under G3X so as to better lay out switches and CB's. Please advise, with yes, no or have you thought about this. Day VFR panel with room for next owner to add IFR Nav.
Van's Air Force
The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!
Thoughts/Advice on panel additions
- Thread starter rick57
- Start date
FlyingDutchman257
Active Member
Hi, there several radio's which can communicate with the G3X. Of course several Garmins but also the Trig remote radio. Unfortunately the same can't be said of the transponders. Also be aware that the G3X 10" screen needs to be lower in the panel as what you show in your mock up. The forward canopy frame square profile will either hit it or blank it. The G3X is well proud of the panel. I have a G3X and G5, switches and breakers in the panel. There's enough space for remote transponder and radio behind the panel.
This is what I'm planning on doing with the -4 I'm working on, with the remote com and transponder and with the GMC 507 and GPS 175. Already have the GSA 28 roll/pitch servos installed. I've been wondering how much space is between the back of the G3X and the f-402C bulkhead? Also curious if it's more of a hassle to have remote com and transponder than panel mounted. Nothing worse than trying to push buttons you can't get your fingers on while getting tossed around on a bumpy ride.
Rick…IMO. You have too much going on. Just my 2 cents.
Panel space is severely limited on the RV-4. Try to get as many avionics installed on a tray right behind the panel. You’ll need to remove the front cowling panel and my recommendation will be to make it removable for easy maintenance and servicing.
Feel free to DM me as I went through this a few months ago. The panel came out beautifully and as I wanted it. A modern, simple VFR panel without costing the bank…but it took time and lots of creativity.
Plan ahead and mock up everything. Bench test and check LRU compatibility BEFORE installation. Ask me how I know
Attachments
climbak
Active Member
I was going to suggest moving all your switches and breakers to a panel on the right side, but it looks like you have fuel gauges there. You might also consider building a small center panel between your legs for items that you'll touch less often. I did that for my fuel gauges and xpndr to get them out of the way. It doesn't seem to get in the way of my legs at all, but I haven't flown it in this configuration yet and I'm pretty short so legroom hasn't been an issue. It looks like you've already got a radio down there currently too.
After talking with Dynon customer service,I am leaning heavily toward 10" HDX. That will allow me to use my current Garmin radio and transponder. The G5 will be a backup for the HDX and Dynon makes ALL the necessary cables and harnesses to hook it all together. I wanted to stay all Garmin but too much expense and extra work.
Jjackh10
Well Known Member
Keep in mind the cross brace a few inches behind the lower panel. Switches barely fit in that space, and breakers are a no go. I had to make a removable face for the switches to get the panel in and out. This pic (of my 10" HDX) was before I figured that out lol. For roughly 1.25" above or below the centerline of those switches, backspace is limited. You certainly can't fit a transponder or radio there. My transponder (GTX-327) is going to have to go in a center console behind the stick.
climbak
Active Member
Anyone know where in the plans that cross brace is? My 4 doesn't seem to have it and I can't find it in the plans.
I think it is the F-402 bulkhead, the crossmember is F-402C and it appears that it was added in a revision in '82.
climbak
Active Member
Ah there it is. Mine was finished in 04, but not sure what version of plans they used. I'll have to see if I can make a new one and fit it in there. I already took that space up with a radio and other things.
This is what I had in my last RV4 (below). 2 GRT screens, both with their own WAAS gps, which will work for enroute IFR GPS navigation. All that’s needed to make it an IFR bird (by your next owner, as you’ve said) is an IFR approach certified navigator. This could be as simple as a remote VHF navigation receiver, like remote VOR receiver. You can do any VHF approach (ILS, LOC, LOC/BC, VOR) and use your GPS as an overlay for SA with this minimal equipment. Enroute IFR GPS direct to navigation is approved using non-approved GPS navigation equipment any time you’re in a radar environment. I’ve done this several times. You’ll need an approved IFR navigation source for the approach or if the enroute navigation source you are using (GPS) goes TU while enroute (highly unlikely). A VOR receiver works for this.
My GRT equipment is compatible with almost all other IFR/VFR navigation equipment. I have a VFR bird with this same level of equipment in my RV6. I have tons of experience flying IFR, but choose to not do so because of my age. If I wanted to make it IFR compatible, I could do the mods to do that in about 2 or 3 days at minimal cost. I don’t believe in building/equipping my airplane for someone else - - unless it’s part of the sale.
First pic - my second RV4. Second pic - my current (last) RV6.
My GRT equipment is compatible with almost all other IFR/VFR navigation equipment. I have a VFR bird with this same level of equipment in my RV6. I have tons of experience flying IFR, but choose to not do so because of my age. If I wanted to make it IFR compatible, I could do the mods to do that in about 2 or 3 days at minimal cost. I don’t believe in building/equipping my airplane for someone else - - unless it’s part of the sale.
First pic - my second RV4. Second pic - my current (last) RV6.
Attachments
Put the Xponder on a tip out hinge, on the right sidewall (behind your knee, in front of your hip.). Works great for me and is off the panel, out of the way, but easy to reach if I need to change a code.
Jjackh10
Well Known Member
I thought about mounting it face up in an armrest there. I will try to visualize a hinge setup, anything to make the little cockpit feel bigger.
Jjackh10
Well Known Member
climbak
Active Member
Thanks for the picture. It looks like on mine they mounted the panel right where the support goes. I've already installed a bunch of things down low there so I'll fab up a support that will fit sometime soon.
I did add a support midway in the avionics bay, but that's more of a support for the radio and terminal blocks.
I have a few clarifications.
1. To the best of my knowledge the FAA still will not approve any gps for use under ifr unless the gps has the appropriate TSO. But, if you call up center and ask “How about a radar vector on a heading (track) of 033 for the next 200 miles”, they know that you plan to monitor your non-TSO’d gps so they’ll usually approve it. That’s why, as you said, radar coverage is required.
2. VOR approaches are getting harder to find. And most ILS approaches require some additional navigation equipment to ID the FAF, or step-downs, or missed approach procedure, etc., such as DME or a VOR cross-fix. Using the non-TSO’d GPS for this is not strictly legal. I’m fortunate to have a near by airport (KSCK) with an ILS that needs just one VOR cross fix, and this is handled nicely by the SL30 (that can simultaneously put out the ILS data and the VOR radial) and the GRT efis’ HSI (which displays the LOC/GS with the usual moving bars, and the vor bearing as an RMI needle).
3. Not positive I agree with your statement that a gps outage is highly unlikely, having experienced two of them myself.
Have you thought about a remote mounted transponder that you control through your G3X/Dynon? Generally, you only need to set the code once a flight, so even though you have to get to the transponder number pad, I find that it's not a big deal. It would free up a little panel space, which seems to be at a premium in the -4.
Last edited:
Jjackh10
Well Known Member
I have, but all the remote ones I'm aware of have ADSB out. I don't want that.
I have a Sandia STX 165R (remote) transponder mounted behind my panel, controlled through my GRT EFIS. Very easy to change codes and it’s a mode C - the ADSB out is via the uAvionix Echo. I don’t think the echo is available anymore, so not sure what they are recommending for that.
Jjackh10
Well Known Member
I will look for one of those. Are there other remote mount, non-adsb, that would work with my dynon hdx?
The default Dynon xponder is a re-branded Trig TT-22. If you don’t plug in the gps data to it, it will default to mode S, no ADSB-out. But I don’t think that’s what you want, either.
To expand on Bob's comments, the Dynon and the Trig transponders also have different software. They are NOT interchangeable.
Jjackh10
Well Known Member
So if I'm understanding correctly, I could buy the Dynon transponder but not connect the gps. That would satisfy the transponder requirement for an airplane with electricity but not provide ADSB out, that would then be required to be turned on even in the rural world I live in?
I am in process of the IFR upgrade. A couple of things. I did a simple panel G3x wit the G5 as a backup. The GFC 500x autopilot, GNC 355 Gps, GNC 215 VOR. Everything else is a remote including the GTX 345R transponder.
I’m an aircraft mechanic and opted to put all the switches and circuit breakers on a separate sub-panel below the main panel to facilitate better access without removing every f****ing thing.
That is correct. Without ADSB-out you will be restricted to below 10,000'MSL (with some exceptions), no Class B or C areas, not within 30 nm of Class B airport, etc. But the reason for my cryptic comment ('I don't think that's what you want') is that the TT-22 is still a mode S transponder and, even without ADSB-out, it replies to "pings" with your N number (or hexadecimal equivalent), so it is not truly anonymous, if that is your goal. You could call (or ask here) for someone really knowledgeable about the Dynon transponder, ask "What if I leave the transponder set up table blank where it asks for the N number?" e.g., Does it still work, but as a mode C (no ID data is sent out), or does it not function at all with the table blank? I don't know the answer.
I have decided to go with the 7", thanks for the heads up!
