I may have used the wrong terminology. When I said the network needs to be enabled, what I meant was the phone can't be in Airplane Mode. This has nothing to do with the data service, internet or wifi, although the phone wants wifi enabled too.

I just don't understand the need to turn off the GPS receiver in Airplane Mode. I know of a number of aircraft with built in FAA certified GPS systems in which the pilots bring their personal Garmin receivers because the maps are better. There is no interference with the aircraft avionics.