My flight instructor and I both have requested lower altitudes during a cross-country flight to shoot out texts for whatever reason. You didn't even need to hold on to the yoke (unless the aircraft has been improperly trimmed or trimmed for other maneuvers.) With that said, In the military, it's probably a different story. (Speculating) You probably wouldn't fly with your phone. I know some branches have had issues with service members using their phones in the middle of an operation. My friend (currently in the Navy and has deployed several times on a cruiser) would sometimes message me whenever he was close enough to the coast. He mentioned that he had to be careful with how he communicated because several sailors were leaving their location services on and were being spotted on some apps. My friend said he opened a social media app and randomly found a few of his crew members' profile pics just randomly floating in the sea right on top of their location. It's been an issue near front lines as well, where some service members were hacked by opposing forces to figure out where they were headed or what they were doing. In military aviation, I doubt anyone is using their phone. Even if it is allowed, you're either high up in the air en route to where you need to be, or you're training or doing something that'll require your full attention. Maybe a helo squadron flying low could get away with it?