Airplane mode refers to a setting in mobile phones and devices that blocks the network or cellular signals so users are unable to make voice calls or send and receive SMS or text messages.  By setting a cellular phone to airplane mode, the cellular or network signal will be lost but users will still be able to use the other features of the phone like music, apps, and games.  Many airline companies around the world do not allow mobile devices to be operated before, during, and after a flight.  The basic reason for this is that the signals transmitted by mobile phones and devices may interrupt with the plane’s navigational and electronic instruments.  For safety reasons, passengers on a plane are often asked to turn their mobile phones off or set their device to airplane mode.

In airplane mode, mobile phone users will not be able to make a call or receive calls from outside the plane.  The sending and receiving of text messages are also blocked when airplane mode is turned on.  Many smartphones also have Bluetooth and Wi-Fi capabilities and these are also typically switched off when the airplane mode is set to ON.  In the same way as network or cellular signals, the transfer of data involved in connecting to Wi-Fi or to a Bluetooth-enabled device may also interfere with the electronic signals that are used inside the plane.  In many cases though, only the cellular signal is advised to be switched off.  If all Bluetooth and Wi-Fi features are also turned off using airplane mode, some airlines allow passengers to switch both these features back on again during a flight.

In the interest of safety, all passengers of any airline must follow the guidelines and policies regarding mobile phone and device use before, during, and after a flight. Some airlines allow the use of mobile phone features only during a flight but not during take-off and landing.  Other airlines meanwhile do not allow mobile phones to be turned on for the entire duration of a flight.