Answer Description
The best option is to instruct the user how to disable mobile data for the duration of the trip. While this is disabled they cannot access the internet using their cellular connection but could still use WiFi, Bluetooth, etc. This is supported by all major smart phone operating systems. Mobile data may also be referred to as cellular data.
Wikipedia
Airplane mode, Aeroplane mode, Flight mode, Offline mode, or Standalone mode is a setting available on smartphones and other portable computers that, when activated, suspends radio-frequency signal transmission by the device, thereby disabling Bluetooth, telephony, and Wi-Fi GPS may or may not be disabled, because it does not involve transmitting radio waves The name comes from the prohibition by most of the airlines of using equipment transmitting radio-frequency signal while in flight using airplane mode prevents devices from transmitting When the "Airplane mode" is activated, it disables all voice, text, telephone, and other signal-transmitting technologies such as Wi-Fi and Bluetooth
Airplane_mode - Wikipedia, the free encyclopedia