''What's the worst that could happen? It's just a phone. It's not like I have a bomb or anything? If it's that easy to damage a plane with a telephone, why don't terrorists use them all the time?'' You probably thought all these to yourself or even shared it with the cabin crew. Well let's tell you this, there's no way you can damage any engines on the plane with your telephone but there are still some risk factors. Let's see what they are and learn why we have to turn off our phones during a flight.