The aircraft is asked to keep in mobile airplane mode while in flight. Cause- Mobile signal can cause network jam on the ground. During fast travel and when it is more than 10,000 feet, the phone signal tries to communicate with different towers and sends strong signals because it receives weak signals from the tower . The mobile tries to increase the signal so that the communication with the tower is intact. As a result, whenever the signal of the mobile phone wants to connect to its tower. At that time, the sound of 'ko-ko' may be in the pilot's sound system. However, experts believe that if the phones of ordinary passengers are open, they are not likely to have such problems. Because they don't go to the cockpit. You may have heard unpleasant sounds from an audio system when there was a mobile next to that audio system. As can be seen if there is a mobile phone next to the TV , the phone actually hears a bad sound from the audio system of the television. Because the radiation of the phone can be strong many times and it can be up to 8 watts. So imagine for a moment that the radiation from the mobile during an urgent message from the airport caused the noise in the pilot's headset. Imagine for a second you were transposed into the karmic driven world of Earl. You can imagine how annoying it can be on a pilot's headset . The main problem is that the signal emitted from the tower of the mobile can disrupt the signal of the airplane which can cause various problems to the aircraft. Another important reason why you should keep your mobile in airplane mode is that you don't want to bother the pilot. So you should keep the phone airplane option on , letting the pilots do their job properly.