Flight Mode (Airplane Mode) : On or Off

Traveling by plane has been one medium of faster transportation for few decades. Crossing miles & miles within a minute has made our life really simple. Air Transportation somehow signifies we are quite familiar with the fact of turning our phones into flight mode or airplane mode and turning some of our electronic devices off.

Question may arise why we need to do this stuff especially, during take off and landing. Why electronic device should be turned off during flight? Can the 900$ phone take 90 million dollar jet to the ground and burn it with its own jet fuel, just because

we didn't turn our phone off to the FLIGHT MODE?

Airplane cockpit i.e. the front part of the plane where pilot takes control over the plane is filled of highly sensitive equipment required for navigating, communicating and other requirement for safe flight. All electronic devices have electromagnetic field that can interfere with the radio frequencies. It’s not only the cell phone but there is electromagnetic radiation that emits from every electronic personal devices and interfere with the the plane’s navigation system, communication system. The electronic signal can also interfere with the signals between the plane and radio station during takeoff and landing.

Safety officials worries that the electromagnetic radiation might interfere with this sensitive equipment in the airplane and creates safety issues. Devices like portable DVD found to drift airplane GPS system few degrees (research from few years ago). This thing can be resolved by turning it off.
If you argue with the flight attendant over using cell phone, you could be arrested and taken off the flight. If you intimate the flight attendant, you could be jailed for decades.

Likewise, issue of frequency reuse also happens simultaneously.
The frequency can’t be distributed all over the places with single tower. So the cell phone company establishes tower from place to place to reuse the same frequency. With car driving along and people communicating from office and home, there is a little chance that this frequency will overlap in another area and create problems. 
It wont be hard to make a call when you are on a ground. You just communicate through single frequency with single tower. However during the flight when you are flying 500 miles per hour moving around the signal will reach out in different towers with the same frequency at same time and interfere with the ground base cell phone system. And increases the possibility to interfere with the plane’s equipment.

In America because of the Federal Communication Commission (FCC) one should put their phones with airplane mode on. FCC regulations ban the use of cell phones on planes in order to ‘protect against radio interference to cell phone networks on the ground.”

Present time most of the airplane flight provides on air time. Newer plane technology uses the pico cell which acts like a mini cell tower or base station on board and allows the plane on a flight and tower on the ground to interact normally. Basically, the range of a pico cell is 200m or less which is suitable for the plane on flight. Air France was the first airline to allow the use of cell phone in their planes to mail text make receive call.
“It’s never been proven that a mobile phone signal has interfered with the navigation performance of the aircraft. But just because it’s never happened doesn’t mean it will never happen.”

-A pilot tells Business insider