The reason that the 5GHz WiFi band is disabled during flight (airplane) mode is comply with local regulations. There are regions in the world where the usage of the 5GHz band is not allowed to be used for WiFi transmissions. As the Lumia WP8 phones are unable to determine the location whilst in flight mode, the phones disable the usage of the 5GHz WiFi band in order to comply with regulations.
- I cannot connect to the internet using a mobile data connection on my Lumia phone
- I cannot share my Lumia’s internet connection with another device
- Is Adobe Flash capability supported on the Lumia phones?
- I have seen change in Wi-Fi connection signal strength after the update was applied to my Lumia.
- Cellular data connection or MMS sending doesn't work on my Lumia 521 when using "Wi-Fi Calling"