Supporting your counterpoint: I am a cell tower geek and I have an app on my phone that records the cell ID of every tower my phone attaches to. I once flew from Wellington to Auckland on an Airbus 320 and forgot to turn off Airplane mode. Arrived into Auckland and my app had logs around a hundred or so cells my phone managed to attach to. So it can happen. I've also had successful two-way text conversations while still in the air but low enough (e.g. when descending on approach to an airport). Saying a plane is a Faraday cage is a bit extreme but I do acknowledge the steel tubing around you will reduce the signal strength by quite a bit -- but not quite enough to 100% block out the signal it seems.