Airplane mode is a setting available on many mobile phones and other electronic devices that, when activated, suspends many of the device's signal transmitting functions, thereby disabling the device's capacity to place or receive calls or use text messaging – while still permitting use of other functions that do not require signal transmission (e.g., games, built-in camera, MP3 player).
The name is derived from the fact that it permits the user to operate the device while on board a commercial aircraft while in flight, where the operation of mobile phones and other devices that send or receive signals is generally prohibited due to the common belief that they can potentially impact aircraft avionics or interfere with ground mobile networks. Other names include flight mode, aeroplane mode, offline mode, and standalone mode.
When the "airplane mode" is activated it will disable all cellular services (GSM, UMTS, LTE) as well as 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. Receive-only technologies like FM radio and GPS still operate if the device is so equipped. Some models disable GPS and other passive features, but this is inconsistent among manufacturers, since these latter functions are permitted on some aircraft and not others.
In a revised review as of October 2013 the FAA has described the usage of electronic devices in "airplane mode" - the cellular services are disabled (disallowing any airborne calls) while Wi-Fi may be used if the carrier offers such a service. Short-range accessories such as Bluetooth are always permitted. The statement is only a recommendation citing the common allowance by aircraft operators based on the fact that airplanes can tolerate the usage of these personal electronic devices (hence their usage may still be completely prohibited on some airplane models).
Although it is not possible to send calls or text in airplane mode, devices such as some Nokia smartphones allow the user to make an emergency call regardless of the fact that the phone is in airplane mode, while other mobile devices such as earlier Sony Ericsson devices only allow active mobile network connections (regardless of whether it is an emergency call or not) after the device has been turned off and restarted to normal mode.
A secondary feature of airplane mode is that it reduces power consumption by shutting down various onboard transmitters and receivers.
Legal status in various nations
- India : On 23 April 2014, DGCA amended the rule which bans use of portable electronic devices and allowing their usage in all phases of flight. 
- "iOS: Understanding airplane mode".
If allowed by the aircraft operator and applicable laws and regulations, you can re-enable Wi-Fi and Bluetooth while in airplane mode
- "Android: AIRPLANE_MODE_RADIOS".
A comma separated list of radios that need to be disabled when airplane mode is on. This overrides WIFI_ON and BLUETOOTH_ON, if Wi-Fi and bluetooth are included in the comma separated list.
- "FAA to Allow Airlines to Expand Use of Personal Electronics". Federal Aviation Administration. 2014-10-31.
Cell phones should be in airplane mode or with cellular service disabled – i.e., no signal bars displayed—and cannot be used for voice communications based on FCC regulations that prohibit any airborne calls using cell phones. If your air carrier provides Wi-Fi service during flight, you may use those services. You can also continue to use short-range Bluetooth accessories, like wireless keyboards. [...] The PED Aviation Rulemaking Committee (ARC) concluded most commercial airplanes can tolerate radio interference signals from PEDs. In a recent report, they recommended that the FAA provide airlines with new procedures to assess if their airplanes can tolerate radio interference from PEDs. Once an airline verifies the tolerance of its fleet, it can allow passengers to use handheld, lightweight electronic devices – such as tablets, e-readers, and smartphones—at all altitudes
- India amends rule on inflight usage of Mobile phones