Nikon D6 Reference Manual page 981

Airplane Mode
Select [Enable] to disable the camera's built-in Bluetooth and
Wi-Fi functions.
•
The wireless functions of optional peripheral devices
connected to the camera can only be disabled by
disconnecting the devices.
Connect to Smart Device
Connect to smartphones or tablets
(smart devices) via Bluetooth or Wi-Fi.
G button U B setup menu
G button U B setup menu
B The Setup Menu: Camera Setup 929