In regards to airplane mode, it will turn off WiFi, Bluetooth and cellular. However, you can turn on WiFi and WiFi calling when in airplane mode, thus still keeping your cell tower connection and Bluetooth off. However, it is important to note that even if using a VPN while in airplane mode with WiFi calling turned on, your WiFi calling will not be routed through your VPN, but rather separately to a cellular WiFi AP. Cell providers can track your location via WiFi calling even if you are using WiFi calling with a VPN and airplane mode on just as they can track you by GPS through E911 even if you have Location (GPS) turned off.