The reason is different. During the flight, the signal from the mobile phone will interfere with the work of the land masts of cellular communication, since the speed of the aircraft will make it possible to appear very quickly in several cells simultaneously.
Actually, there is the problem of mobile operators and mobile device manufacturers themselves, and not aviators in any way. But since the passenger with a mobile phone on board the aircraft, the crew is partly responsible for ensuring that during the flight there is no interference to ground services.
Of course, the ideal solution is to include on board a certain cellular frequency suppressor. He could "cover" on the air all the mobile phones on board the aircraft.
The idea is not new, but so far it has not been implemented at the industrial level. The difficulty is that the signal suppression device must somehow, for example, with the help of many short antennas, be located throughout the entire volume of the passenger plane during its construction, hiding inside the casing.
Doctors say that mobile communication, although not a serious health hazard, but with a lot of radiated antennas in a closed small space, an unpredictable effect may appear. True, only individual doctors say so. In principle, the plane uses many other frequencies during the flight, and nothing bad is noticed.
It seems that the aviation suppressor of cellular frequencies (in common language - “jammer”) will appear on all civil aircraft. Moreover, there is a precedent for the use of “jamming” mobile phones in theaters and museums, as well as in libraries and other places where silence is required.
Back in 2014, an experiment was conducted in Moscow theaters on the use of cellular signal suppressors. The measure was forced. Requests to turn off the phones at the time of the performance were not performed by all viewers. There were frequent situations when, at a tense moment on the stage, a mobile phone started ringing loudly at someone.
As the test of suppressors showed, they did not act very effectively. Simply put, it required a complex screening of the entire auditorium, which was a problem. Another difficulty is with the inclusion of the suppressor: the cell phones and the theater workers themselves became "dumb", as the equipment "turned off" all signals without ranking. Another point is legal. Telecom operators (not all, but some) were outraged that their customers were illegally blocked. And this, they say, affected the profit.
But let's imagine this situation. Suppose some criminals adjust their actions on mobile communications. It takes time to block their phones through telecom operators. Installing a signal suppressor will temporarily make the mobiles of criminals useless. And this is exactly what is needed for operational detention. Of course, if the disposal team has all the legal authority to block.
As we see, there is a need for a suppressor of cellular signals. The movement of technical progress towards the creation of effective suppressors for specific cases of life is coming. What happens in the end? Wait and see.