Peter wrote:
I cannot imagine any context in which playing back a call made to me would do me any good, because any reasonably competent ATCO (basically any ATCO in most if not all* of Europe) will give me at most a few seconds to respond to his/her call and then will be onto me pretty fast.
I am not sure that is the point. I seem to recall in the advertising material the point was that you played back the recording as the read back and of course the read back could only ever be correct. It always seemed to me complete nonesense as it would just seem “weird” to playback the instruction you had just be given but perhaps it does meet the legal requirement. It would be interesting to see what sort of reaction you actually got! I suppose on a positive point have we all had occasion where you give the correct read back, are very naughty not recording the whole clearance on your knee pad, but committing it to memory, and then when taxing suddently thinking was I actually cleared to cross x. At least you can listen to the recording rather than asking ATC to confirm.
The audio playback feature can cause confusion when flying with two pilots. If one pilot is replaying radio messages and the other pilot is not aware of it, he will respond over the radio to the recorded call. I’ve been through that 
Thank you for answers – I will probably stick with Gamin because it matches the rest in the stack .
I do use it. I find it quite handy when I am instructing as I’m sometimes not sure if a call was for me or not
I cannot imagine any context in which playing back a call made to me would do me any good, because any reasonably competent ATCO (basically any ATCO in most if not all* of Europe) will give me at most a few seconds to respond to his/her call and then will be onto me pretty fast.
London Control will give you considerably less than a few seconds 
There are “non clearance related” calls from ATC where a lack of pilot response would not be chased by ATC, but only if they are really busy. I just can’t think of a good example at the moment. Stuff like requesting 20 degrees left to avoid and getting it approved is generally not acked… I wonder if that’s really correct? I think ATC give pilots slack on those because anybody asking “to avoid” is probably working hard.
One scenario where I may want to listen to something over and over is a barely legible ATIS. Not uncommon in France, although I don’t recall a recent case. But one can just listen to the broadcast then… I suppose a local playback would save having to wait for the French version to done before you get the “English” one again.
* the cases where ATC issue a clearance and don’t expect a readback are where they can’t speak English and don’t want evidence on the tape
you send freetext and emojis
Makes me laugh to think of the 4-byte emojis which used to break the EuroGA PM system. I think it strips them out nowadays.
CPDLC has been a thing “with a great future” for about 20 years
How would “read-back” work, to ensure I haven’t misread the text? Re-type? Or text-to-plane, voice-to-ground?
I can see a touchscreen with likely standard radio phrases, where normally you just got one, but is it certain you read the text correctly, AND hit the right button?
W10 and Android word prediction make very wary.
Is something like this already working with airlines en-route?
( Reading message before sending to check if any changes have been made automatically.)
Digital recording ATC would work brilliantly. It would just work exactly as it does now… except you could just transmit without waiting for a gap and it gets queued to receive. You could also filter out messages to other aircraft.
Pigs would probably fly before this happens! Love the idea though.
In a multi-crew environment and/or with a hyper-reliable autopilot, certainly… and fantastic for the reading end. I would love to just get the clearances as text, and the currently valid clearance elements displayed, and the ability to transfer that into the FMS at the touch of a button…
But when having to hand-fly in turbulence, just setting a new squawk can take half a minute, and that is only four digits. How long does it take to type “unable to maintain FL180, severe turbulence”, in turbulence?
My experience is exactly the same. Pointless feature.
What we need is text based ATC.
