The Smartbox / Media Streamer can be turned on and used as a wired Flash memory reader on any airplane if and when computer and mobile devices are allowed to be turned on and used.
Use of the Smartbox / Media Streamer as a wireless device is dependent upon each flight. Many flights allow WiFi access. This is different than cellphone carrier access. Usually, if wireless video or internet service is allowed on the flight, then WiFi is allowed.
Please check with your particular airline and always follow the rules of each particular flight.