I believe aircraft mode automatically disables wifi, bluetooth, mobile signal and maybe other facilities but many airlines offer wifi on board now.
BA’s connection requires Aircraft Mode to still be selected but then to enable wifi to connect to their onboard system, assume the others will be same or similar.
So am curious, what is the potential problem with mobile signals that only wifi is enabled.
There are 2 main potential problems with mobile signals as opposed to WiFi.
The mobile transmits at a much higher power level. Typically 3W vs the 100mW of WiFi, thus increasing the risk of interference to the aircraft’s on-board systems.
Transmitting from the air can cause problems for the mobile network itself. Your phone will be heard by multiple base stations and this will upset the way the cell structure works.
Frequency is different. Some mobile frequencies (800-900Mhz) are lower than WiFi/Bluetooth (2.4GHz) and that’s why they can “penetrate” deeper in various parts of the aircraft.
Also, the cell signal level is increased to the max in “search” mode, when you lose cell connection, to help with reception in fringe areas. WiFi signal level is constant.
However 50% of the people in the plane will just keep facebooking or whatnot till the last moment (taking off) and then, when they lose signal, just shove their phone in the pocket. They are the ones with discharged phones after an 8 hour flight, because of all that signal searching…