If you’ve ever flown before, you will definitely have heard the announcement. After you have been informed about the numerous safety features on your aircraft, all passengers are asked to activate flight mode on their devices i.e. mobile phones, tablets etc. But one question will have inevitably popped into your head. What would happen if you didn’t?What is flight mode?To know for sure, we first have to explain what flight mode actually means. To be more specific, as soon as you turn this mode on, all the wireless functions on your device are switched off. This includes your mobile data, location services as well as your WiFi and Bluetooth connections.More and more manufacturers are now equipping their devices with a special button that can be used to enable this function and as soon as you board the plane, you should switch it on.Why is flight mode so important?Nowadays, airlines make it very clear that every mobile device onboard a plane has to be in flight mode for the flight to be as safe as possible. The Daily Dot explains that this is because the electromagnetic signals your device emits could interfere with the onboard communication instruments in the cockpit which, of course, could be fatal if things go wrong.And then there is also another, more official, explanation for this rule. The U.S. Federal Communications Commission is more concerned about the way these devices could interfere with radio towers on the ground. They have revealed that signals from mobile phones that have been left switched on and are not in flight mode can be picked up by radio towers even from 10,000 meters above the ground. These signals could consequently mess up the networks and disrupt the reception on the ground.Can you still use the features on your phone despite enabling flight mode?Your mobile data must, of course, remain switched off during the entire flight. That is why it is not possible to make calls, send texts or Skype. But depending on how modern your aircraft is, you don’t necessarily have to do without an internet connection during your flight.As it turns out, flight security authorities allowed passengers to use Bluetooth and WiFi on planes in 2013. And if the services are offered on board, you are able to surf the internet from high in the clouds. With most phones, the WiFi function has to be manually restarted after you have switched your phone into flight mode. But be careful what you post, because this pilot recently got fired for posting a picture mid-flight. Don’t snap and fly!Flight mode is also useful for even after you have landed safely. When activated, your device saves battery and also charges faster than usual. Give it a try!