A Q worth asking is whether any avionics installers here have installed this and what they found.
My usual avionics engineer says he’s installed one so far. Since there is practically no cost involved (i.e. a Radiospares PTT switch and 3 ft of wire), I’ll try it and let you know.
For expert GNS430 knob-twizzlers the GTN’s touch screen and abbreviated frequency are probably gimmicks, but I see them as a way of paying more attention to other “pilot” tasks (pouring coffee, eating breakfast, or even just gawping out of the window). Voice command seems a logical next step, if it works. With a single GTN, it should make switching between display pages, say for a quick glance at terrain or default nav, just a little easier.
I think the GTN touchscreens work well. Question is how good the recognition is so whether you can really rely on it working well 99% of the time.
Yes, that’s the question.
The manual (see post #1) says don’t use unless you get at least 85% correct. I guess the only way to know is to try it.
85% is horrible. Given that most items involve multiple digits, the effective error rate is more like 50%, and 25% after two attempts.
@Cobalt, I think you may have misread the Garmin manuals. There’s rarely any need to tell a GTN which frequency to tune. It knows all that stuff. We can just tell it which station to tune (for instance, “Tune Destination Weather”) and it will offer the relevant frequency or frequencies.
Of course, someone who is used to a panel with 15 year old aero-jumble radios can punch (or even twiddle) frequencies into a GTN digit by digit, but that’s like selecting gears in an automatic gearbox. Even Citroen drivers rarely do that.
Fair enough, but in real life I get about five frequency changes in the departure and climb from Biggin (Approach, Thames Radar, London Control x 2 or 3) none of which are known by name, so the general idea of just pressing the “voice command” button during the readback was very appealing…. I guess my wife will continue to do that, then. Her accuracy is 99.9% plus.
Of course, wives are always right. Maybe also better company on a long flight than talking to a GTN 650. But some are more expensive valuable than 3 ft of wire and a PTT button. 
Jacko wrote:
@Cobalt, I think you may have misread the Garmin manuals. There’s rarely any need to tell a GTN which frequency to tune. It knows all that stuff. We can just tell it which station to tune (for instance, “Tune Destination Weather”) and it will offer the relevant frequency or frequencies.
Yep not sure that will work for London Control, Maastricht or Langen.
Automatic frequency selection will not work in any phase of European IFR enroute flight, and won’t work for most departures and approaches. And transponder setting is hardly a common thing. But maybe there are other things in the avionics which one can control? I do suspect it is a gimmick because if you have to press one button to talk to it, then why not press the real button? It might be quite clever if you can assign macros e.g. to select a particular screen config on a GTN750. Flipping between the fuel status and the enroute map is one common thing. OTOH that is exactly why one has an FMS (KLN94) and an MFD (KMD550), or a GTN650 + GTN750 
