My Lumia 520 is stuck in Flight Mode. How do I free it?

[Windows Central Question]

I've tried a reset but to no avail. Any suggestions?

 

[RumoredNow]

Try this...

Plug into the mains. While plugged into AC current, power off the phone. The phone will reboot since it is plugged into the charger. This seems to reset a bridge between motherboard and daughterboard as reported here.

http://forums.windowscentral.com/nokia-lumia-1520/299878-3.htm#post2853178