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Rate my avionics kit.... please

agent4573

Well Known Member
Looking for any suggestions on the following list of avionics. We're building an IFR platform that can go cross country safely. We're not looking to fly hard IFR all the time, but want the capability in case we get caught somewhere. Our goal is 2 independent COM radios, GPS primary nav, NAV radio backup. Its all going in an RV7.

GDU 460 10.6" G3X Touch x 2
GNX 375 ADS-B XPNDR & WAAS GPS
GNC 255 Nav/Comm w/ VOR/ILS
GMA 245R Remote mount comm panel/bluetooth receiver
G5 Backup Display
GTR 20 Remote Comm
GSA 28 AP Servos x 2
GMC 305 AP Control Head
GEA 24 EIS
GAD 27 Adapter
GAD 29 ARINC 429 Link
GAP 26 AoA Probe

Here is are my primary questions:
1. Neither comm radio has the option of bluetooth in. Whats the best way to get bluetooth music and phone ability into this system?

2. The GNC 255 is our backup NAV solution if we every lose the GPS, but losing the GPS means losing the DME capability of the 255. So we're now on a single VOR with no DME. Would it be better to use the SL30 which allows you to tune the standby NAV frequency to a 2nd VOR?

3. Both the GNC 255 and the GTR 20 have intercom functionality. If we keep both of these boxes, which should be used for the intercom, which should be com 1 and which should be com 2?
 
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You will have to have an audio panel with that configuration. You have two com radios. So while the GNC 255 and GTR 20 each have their own built-in intercom (255 mono and 20 in stereo) they are just that, intercoms. Neither radio will switch audio like an audio panel will. Your headset audio and microphone circuits will be dedicated to whichever comm radio they get wired to and won't have access to the other comm.

The obvious solution for an EAB would be the Garmin GMA 245 or 245R audio panel with built-in Bluetooth capability. That would bring everything together.
 
Agree with Jim 100% on the audio panel.
I would use the GMC507 AP panel.

If your budget allows, I would replace the 255/375 and go with a GTN650xi with built in VOR/ILS, makes ILS transitions automatic, bigger screen, and VNAV functions via flight plan are super cool, top it off with the GTX45R transponder.
 
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Good info, thanks. We were confused since the g3x advertises it can control 2 remote radios. We assumed that meant it could do it without the need for an audio panel as well. We can do the 650, but honestly the single point of failure worries us. I know the gps and nav/com are powered separately, but if we do get water incursion or any physical type damage to that box, it takes out both nav sources in a single event.
 
SNIPWe can do the 650, but honestly the single point of failure worries us. I know the gps and nav/com are powered separately, but if we do get water incursion or any physical type damage to that box, it takes out both nav sources in a single event.

But consider the typical 650 install into an IFR panel includes:
- An EFIS system that has it’s own GPS antenna and receiver (at least the SkyView does).
- An independent Comm #2.

My point, for a standard IFR install the GTN-650 is not a single point failure risk - it can die and for other than a hard IFR approach you will not be degraded at all.

Carl
 
Carl,

Can you explain the last sentence a bit more? If we lost the 650, it takes with it the certified GPS and the NAV radio, which means VFR only with Com2 for voice. Its not just approach, I can't legally fly any leg on an IFR flight plan with just an EFIS.
 
Carl,

Can you explain the last sentence a bit more? If we lost the 650, it takes with it the certified GPS and the NAV radio, which means VFR only with Com2 for voice. Its not just approach, I can't legally fly any leg on an IFR flight plan with just an EFIS.

Yep, you are correct and you will not be IFR legal - BUT you will still be flying and navigating. Shoot fire when I’m flying IFR the GTN-650 is cooking along, but the practical information to keep the wings level, on course while avoiding terrain, weather and traffic is on the SkyView.

Risk management - have a plan for failure of any one component. If your GTN-650 (or whatever is your TSO certificate GPS navigator) dies you can fly in the clouds but not do a precision or non-precision approach, and you will not be technically legal for in route GPS navigation. Talk to the controller, tell them what is going on and that you need to do a visual approach. If the airport you are going to ceiling is below visual minimums, let the controller recommend where to go.

Just like the old days when the vacuum pump failed and you lost the DG and AI. You still flew the plane.

Carl
 
Sounds like we're on the same page for the most part on what pieces get us what benefits. We're not comfortable with losing a single box and going from an IFR platform to a VFR platform. Granted you'll still have all the ability to safely fly with the loss of the 650, but I think we would like the ability to legally fly with the loss of our GPS source as well.

I did some more research based on other comments about the COM panel and a few posts I found indicated we could get away without a comm panel if we did some switch and relay wiring, I think we're just going to add a remote mount GMA 245R comm panel to the sub-panel structure and call it good to go. I like all the features you get with it, and the girlfriend likes that it doesn't take up space on the panel.

Still curious about what people think between the 255 and SL30.
 
Still curious about what people think between the 255 and SL30.

IMHO the SL30 is the best nav ever made, in part because it can track a localizer AND simultaneously a VOR. Take a look at the LOC29R at SCK. Imagine your gps died (or is being interfered with). The SL30 is all you need to track the localizer and monitor the cross radial at the final step down fix. (On my GRT HX the loc is on the CDI, cross fix on an RMI needle). Also, if contemplating no audio panel, as you are, there is an option to send nav ID audio out the com audio out line, and select it from the SL30 front panel. And, the -30 doesn’t need arinc inputs, just rs232. Only downside - and it’s not trivial - is that these boxes haven’t been made in some time, repair may be difficult as parts get hard to find. BTW, I also don’t use a full-up audio panel, just an intercom with a lot of unswitched inputs, plus a single panel switch to select com1 or com2 for mike and PTT lines.
 
Audio Panel Questions

Sounds like we're on the same page for the most part on what pieces get us what benefits. We're not comfortable with losing a single box and going from an IFR platform to a VFR platform. Granted you'll still have all the ability to safely fly with the loss of the 650, but I think we would like the ability to legally fly with the loss of our GPS source as well.

I did some more research based on other comments about the COM panel and a few posts I found indicated we could get away without a comm panel if we did some switch and relay wiring, I think we're just going to add a remote mount GMA 245R comm panel to the sub-panel structure and call it good to go. I like all the features you get with it, and the girlfriend likes that it doesn't take up space on the panel.

Still curious about what people think between the 255 and SL30.

Just to add on to the info already provided regarding the audio panel, the GMA 245R sounds like a good fit. Per the marketing material for the G3X, you can control two COM radios from the GDU, allowing you to change frequencies, and trigger a frequency swap on each of them, but the GDU does not take the place of an audio panel in a dual COM installation.

The audio panel itself interfaces directly to the audio jacks for your headsets, and does the job of switching between COM1 and COM2, for receiving/transmitting. It also facilitates the intercom capabilities. With the GMA 245R on board, you would disable the intercom on the GTR and GNC radios.


Thanks,

Justin
 
I think we're just going to add a remote mount GMA 245R comm panel to the sub-panel structure and call it good to go. I like all the features you get with it, and the girlfriend likes that it doesn't take up space on the panel.

You will be very happy with the GMA 245R.
 
Two STRONG suggestions:
* Definitely want a 307 or 507 control head. The 305 is an old part. I replaced my 305 with a 307 and glad I did, to get the knobs
* Go with the 650xi as others suggested so that you have more screen real estate to see more of the flight plan.
* I fly with only one comm radio and yes, a second one would be nice but it really isn't that big a deal to fly with one

And if you lose a radio in flight, who cares what's legal and what's not. That's an emergency situation, and as long as you can be safe, that's all you care about. And don't forget that each of the display screens has a built in GPS receiver, all they need is an antenna.

If I had the bucks, I'd put in the audio panel with voice commands. Don't know how useful it would actually be, but might be real cool. I'd love to try one in flight for a few hours...
 
If I had the bucks, I'd put in the audio panel with voice commands. Don't know how useful it would actually be, but might be real cool. I'd love to try one in flight for a few hours...

To the best of my knowledge this feature is only available with the GTN750/GMA35C.
 
Hi! New to the forum and this is my first post.

Does anyone know of a website where various avionics combinations may be entered and see the pricing for that combo? Such as entering the original poster's avionics config for price then removing a comm and gps and replacing with the 650Xi to compare the cost difference?
 
Two STRONG suggestions:
* Definitely want a 307 or 507 control head. The 305 is an old part. I replaced my 305 with a 307 and glad I did, to get the knobs
* Go with the 650xi as others suggested so that you have more screen real estate to see more of the flight plan.
* I fly with only one comm radio and yes, a second one would be nice but it really isn't that big a deal to fly with one

And if you lose a radio in flight, who cares what's legal and what's not. That's an emergency situation, and as long as you can be safe, that's all you care about. And don't forget that each of the display screens has a built in GPS receiver, all they need is an antenna.

If I had the bucks, I'd put in the audio panel with voice commands. Don't know how useful it would actually be, but might be real cool. I'd love to try one in flight for a few hours...

They make a com panel with voice commands?
 
Two STRONG suggestions:
* Definitely want a 307 or 507 control head. The 305 is an old part. I replaced my 305 with a 307 and glad I did, to get the knobs
* Go with the 650xi as others suggested so that you have more screen real estate to see more of the flight plan.
* I fly with only one comm radio and yes, a second one would be nice but it really isn't that big a deal to fly with one

And if you lose a radio in flight, who cares what's legal and what's not. That's an emergency situation, and as long as you can be safe, that's all you care about. And don't forget that each of the display screens has a built in GPS receiver, all they need is an antenna.

If I had the bucks, I'd put in the audio panel with voice commands. Don't know how useful it would actually be, but might be real cool. I'd love to try one in flight for a few hours...

I'll do some more research on the 305/307/507 differences. Thanks for that.

I thought the only thing that had to be done on the GTN navigator itself was to hit the "activate" button for approaches. Everything else should be displayed and programmed through the g3x or through the garmin pilot app and bluetooth transfer. I may be understanding that wrong, but if thats the case, what difference does it make how big the GTN screen is? All I have to do on the navigator is push one button once during a flight.

You're right about the emergency. I have a prejudice against declaring IFE which I should just get over. Loss of the primary navigator in IFR conditions would be cause for declaring, at which point I could just ask for vectors everywhere I needed to go. Tracking a single VOR at that point or using an uncertified GPS would probably be fine.
 
I’d suggest considering your backup small EFIS be from a different vendor and have internal battery backup. That eliminates a class of software related failures.

I have a great dual Dynon panel and chose the G5 as backup for that reason.

David
 
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