Apologies if off-topic, but it seems that there was something vaguely similar (no contact) in Europe today.
Links in Danish:
Københavnerfly udløste stor-alarm - Politiken.dk
Basic jist is:
TAP A320 flying Lisbon-Copenhagen flew for approximately 30 minutes whilst unresponsive to/not in contact with the ground. It covered around 400km in this time and was met by a couple of German F4's. They're investigating a possible technical failure, but the crew was apparently not in contact with the cabin during this period either (although of course it's possible that they chose not to inform the pax of what the problem was).