Have you had the sudden surge of anger when the flight attendant keeps running towards you, nagging you to switch off the mobile phone before take-off when you are in the middle of a serious conversation?
You hear the announcements before the flight takes off from the ground that it is mandatory to switch off phone, “Cellular phones may only be used once the Fasten Seat Belt sign has been turned off”.
However, the Federal Aviation Administration (FAA) does not formally prohibit the use of personal electronic devices on an aircraft.
Then why are airline crew adamant about the mobile phone?
As you are aware, almost all electronic devices, including cell phones, emit radio waves. So, if these radio waves have a frequency similar to that of the navigational apparatus, it might disrupt the aeronautical equipment in the cockpit. Besides, when you are flying at a high altitude, cell phones send out stronger signals, thus leading to network congestion on the ground.
Though the theoretical approach, the network congestion has never caused a single flight crash ever in history. Most present day airlines have introduced, in-flight Wi-Fi services.
The mandatory rule of mobile switch off has only been created as a precautionary principle. Most of the airlines deem it necessary to switch off electronic devices mainly as an act of caution, especially during takeoff or landing, which are the most critical phases of a flight.