Airplane mode doesn’t necessarily turn off the baseband radio, it can still work even if the application OS isn’t talking to it, so you can still be tracked. Also some phones actually have a mux on the camera/mic/GPS so that the baseband can talk to it even if the application OS is shutdown.





I don’t think pinging is necessary, it could just be temporarily turning off airplane mode when you go to make an emergency call.
But I was moreso pointing out that OP’s paranoia over not having a carrier is IMO a bit moot when the baseband is always on, as any tower that’s listening could still see them and track them at least by IMEI. There are some portable hotspots that have an IMEI randomization feature, although I would be worried that you could get banned from the network using that if you actually had service.