This is why you should always put your phone on flight mode before a flight

Note to self, always switch phone on flight mode before take-off. 

Most people would tend to switch their phone on flight mode before a flight, or even switch it off entirely. There was a worry that the currents from your phone could interfere with the electronics of the flight. While this is not the case *sigh of relief*, you should still always switch your phone on flight mode and there is one main reason. According to The Daily Mail, if you don't it may annoy the pilot and air traffic controllers with an unpleasant sound. It's been likened to the sound of a mobile phone coming into contact with speakers and is caused by the powerful radio emissions in the phone. We've all heard that sounds before,'dit-dit-dit-dit'. That sound can ring through the pilots headphones and make it more difficult for them to hear instructions from the air traffic controller.