Can't see any snag with that - so long as the brick is switched off in the air. I don't know what effect the brick's local RF oscillator would have on your avionics if you switched it on......
Judging by the coverage one gets these days on GSM 900/1800 on the SeaCat between Dover and Oostende or Calais, there's a good chance that you could make contact on that even in mid-channel at sea level? But of course it must be OFF in flight!