Garmin GTN 650Xi or 750Xi?

[Matt Ricciardi]

When designing the panel for my VL3, a flip-flopped several times on a threshold question--which IFR-certified GPS? The Garmin GTN 750Xi offers are large, multifunction screen but takes up a lot of panel space and requires most other components to be mounted remotely and controlled via the G3X Touch display. I personally prefer physical discrete components and physical buttons in my panel, so I ultimately opted for the smaller but (almost) equally functional GTN 650Xi.

The Midwest Panel Builders YouTube channel has a good video explaining the pros/cons of each (plus lots of other interesting and useful avionics-related content).

[Jim Harris]

Good stuff Matt.  I have the 750 on my Bonanza, but rarely find myself looking at it.  I want electric flaps so I opted for the 650 on my build as at the time, you couldn’t have the 750 and electric flaps due to panel space.  But per Lukas they have figured a way around that now.  But I’m going to stick with my decision as there is so much screen space on the G3’s i personally don’t think you need a 750. 

[Matt Ricciardi]

On 12/2/2023 at 1:12 PM, Jim Harris said:

I want electric flaps so I opted for the 650 on my build as at the time, you couldn’t have the 750 and electric flaps due to panel space.  But per Lukas they have figured a way around that now.

That's correct.  The new flaps controller is a small switch about the same size as the light switches.  See attached panel drawing.  The flap position is shown directly on the G3X Touch display.

I'm nevertheless sticking with a GTN 650Xi, too.  As you said, plenty of touchscreen real estate on the dual G3X Touch displays, and I'd rather have physical buttons for the audio panel and secondary NAV/COM radio rather than remoting everything.

[Jim Harris]

That’s great.  That’s a major space saver!

[Jim Badalamenti]

Great forum. My VL3 will be complete this summer and head to Oshkosh for display.  I currently have a Bonanza A36 with 2 GTN750xi's and a G500 PFD much like a G3X (G3X actually more robust). I'm different... I like the added screen size of the 750 and plan to stick with it over the 650, I spend a lot of my time with the 750 over similar access on the G500 (or in the case of the VL3 the G3X), it works well for me. I currently access the audio panel thru the 750 and don't miss the push buttons at all and assuming the same will be the case for accessing the nav/com and transponder behind the scenes thru the G3X where again I don't see a lot of time spent on those. Bottom line I'm going for cleaner panel with more display space. 

[Matt Ricciardi]

39 minutes ago, Jim Badalamenti said:

I like the added screen size of the 750 and plan to stick with it over the 650, I spend a lot of my time with the 750 over similar access on the G500 (or in the case of the VL3 the G3X), it works well for me. I currently access the audio panel thru the 750 and don't miss the push buttons at all and assuming the same will be the case for accessing the nav/com and transponder behind the scenes thru the G3X where again I don't see a lot of time spent on those. Bottom line I'm going for cleaner panel with more display space. 

Remoting the radios and transponder should be fine.  JMB strongly recommends a discrete autopilot control panel, however.  That's essentially the panel layout in the factory trainer--dual G3X Touch displays, GTN 750 navigator, and an autopilot control panel.  They also squeezed a miniaturized Trig transponder and radio in the center stack at the expense of manual flaps and relocating the light switches.  See attached photo from my final training flight.  Ultimately a matter of personal preference.

[Jim Badalamenti]

Yes that is basically my panel minus the Trig units as I'm having those components remote. 

[Michael Hodes]

I chose the 650 thinking I would not have enough space for the 750.  With the new electric gear switch, I have plenty of room.  I also have the remote radio and and panel, so that frees up quite a bit of space.  You can see the big empty place on the attached image.

[Jim Harris]

19 minutes ago, Michael Hodes said:

I chose the 650 thinking I would not have enough space for the 750.  With the new electric gear switch, I have plenty of room.  I also have the remote radio and and panel, so that frees up quite a bit of space.  You can see the big empty place on the attached image.

Is that a TOGA button?  I was wondering if anyone was adding one of those.  

[Matt Ricciardi]

11 hours ago, Michael Hodes said:

I chose the 650 thinking I would not have enough space for the 750.  With the new electric gear switch, I have plenty of room.  I also have the remote radio and and panel, so that frees up quite a bit of space.  You can see the big empty place on the attached image.

I'm in the process of finalizing my own panel layout, so this is helpful and timely.

On my panel, the new, smaller electric flap control is currently to the left of the light switches, but I like how you placed it on the lower panel, just above the fuel tank selector.  I'll have to inquire about doing the same.  That space is empty on my panel now.

Just curious, if you're going to stick with the 650, why not un-remote the audio panel and secondary nav/com radio?  You can still control them through the G3X Touch, if you want, but gain the option to access physical buttons directly.

[Matt Ricciardi]

On 1/1/2024 at 2:06 PM, Jim Harris said:

Is that a TOGA button?  I was wondering if anyone was adding one of those.  

Most VL3s are VFR-only due to European microlight regulations, so I suspect JMB hasn't received many requests for a TOGA button.  Good idea though.  Rather than putting it on the panel, perhaps use one of the two unassigned buttons on the control stick?

In a similar vein, I asked about installing a button to manually enter reversionary (split-screen PFD/MFD) mode in the event that one of the G3X Touch displays fails and the other doesn't automatically detect the failure.  Certified G1000 installations have a red reversionary mode button at the bottom of the central audio control panel.  See attached photo.  JMB didn't seem aware that this was possible with the G3X Touch, so I pointed out the relevant portion of the installation manual.  G3X Touch Installation Manual, Section 26.4.6 ("A GDU 4XX can also be manually placed in reversionary mode by wiring Pin 25 to a two pole switch that toggles between open and ground.  When the switch is open, the display will operate normally.  When the switch is grounded, the display changes to reversionary mode.").  Discussion never went anywhere, but maybe worth revising...

[Michael Hodes]

It is a TOGA button.  I asked if it could be on the throttle handle, but the only option for now is on the instrument panel.  I had one on a Mooney and it is invaluable on a missed approach.

I've looked at the G3X training videos and I don't see a good case for the separate audio panel.  The built-in G3X controls look pretty darn good.

I was wondering how the reversionary mode would get triggered.  I'll also ping them on this topic.