Before the plane takes off? Why do you want to turn off your cell phone?

Turning off the mobile phone on the plane is to ensure the smooth flight and the safety of the plane and passengers.

When the mobile phone is used, it will generate electromagnetic waves, which may affect the sensitive computer and navigation system on the plane and disrupt the normal work of the flight system. It is a "killer" that threatens flight safety. Especially during take-off, climb and landing, the mobile phone will search for signals when it is turned on, not only emitting electromagnetic signals when dialing or answering, but also constantly contacting the ground base station in standby state. In the process of its search, although the time of signal transmission is very short, it has strong continuity. The frequency used by the mobile phone is similar to or even superimposed with the electromagnetic wave frequency between the plane and the tower, which may be considered as the command signal sent by the tower, leading to misoperation. In addition, in the case of low visibility, the aircraft needs to use the instrument landing system to land, that is, the blind landing platform on the runway is used to send electromagnetic signals to the aircraft to determine the runway position. Electromagnetic waves emitted by mobile phones are likely to interfere with the signal receiving system of aircraft.

So to be on the safe side, it's best to turn off your cell phone on the plane.