Flight mode

Airplane mode, aeroplane mode, flight mode, offline mode, or standalone mode is a setting available on many smartphones, portable computers, and other electronic devices that, when activated, suspends radio-frequency signal transmission by the device, thereby disabling Bluetooth, GPS, telephony, and WiFi.

The name comes from the prohibition by many airlines of using equipment transmitting radio-frequency signal while in flight; using airplane mode prevents devices from transmitting.

When the "airplane mode" is activated, it disables all voice and text telephony and other signal-transmitting technologies such as Wi-Fi and Bluetooth. Wi-Fi and Bluetooth can be enabled separately even while the device is in airplane mode; this is acceptable on some aircraft. Receiving radio-frequency signals, as by radio receivers and satellite navigation services, is not inhibited. However, even receiving telephone calls and messages without responding would require the phone to transmit; a smartphone in airplane mode is effectively a PDA.

In a revised review in October 2013, the United States Federal Aviation Administration (FAA) made a recommendation on the use of electronic devices in "airplane mode"—cellular telephony is disabled, while Wi-Fi may be used if the carrier offers it. Short-range transmission such as Bluetooth is always permissible. The statement cites the common practice of aircraft operators whose aircraft can tolerate use of these personal electronic devices, but use may still be prohibited on some models of aircraft.

While in airplane mode, most devices allow the user to continue to use their email client or other program to write text or E-mail messages which are saved in memory to send when airplane mode is disabled.

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Wikipedia