Cell towers, without mountains/trees blocking them, can work over 10+ miles and airplanes don’t fly that high… so you are within range of towers while flying unless you’re over the ocean.
However, connecting to a tower that far away requires running the radio at maximum transmission power which absolutely kills your battery. Also the towers reject your phone’s attempt to connect because they are programmed to ignore distant connections when they know a dozen other towers are within a few miles of that tower.
So your phone transmits at high power and constantly attempts to connect to new towers as you fly… without ever actually connecting until you’re landing.
Cell towers, without mountains/trees blocking them, can work over 10+ miles and airplanes don’t fly that high… so you are within range of towers while flying unless you’re over the ocean.
However, connecting to a tower that far away requires running the radio at maximum transmission power which absolutely kills your battery. Also the towers reject your phone’s attempt to connect because they are programmed to ignore distant connections when they know a dozen other towers are within a few miles of that tower.
So your phone transmits at high power and constantly attempts to connect to new towers as you fly… without ever actually connecting until you’re landing.
Being inside a metal tube doesn’t help reception either.