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 devices When activated, this mode suspends the device's radio-frequency (RF) signal transmission technologies (ie, Bluetooth, telephony and Wi-Fi), effectively disabling all analog voice, and digital data services, when implemented correctly by the electronic device software author When cellular phones became prevalent in the 1990s, some communication headsets of aircraft pilots would register an audible click when a cellular phone on the aircraft would transceive a signal This clicking on the headsets became overwhelmingly distracting to airframe control, with more and more phone calls from airplane passengers as time went on
Airplane_mode - Wikipedia, the free encyclopedia