You Don’t Need to Use Airplane Mode on Airplanes

Airplane Mode is designed to prevent your phone from interfering with aircraft instruments, although the risk is relatively low.
It can be used to prevent people from knowing you’ve read their messages. Switch it on before reading an incoming message, and the sender remains unaware.
It resets your mobile network connection, similar to rebooting your phone. It can be used to troubleshoot network problems when you’re getting patchy coverage or your phone is having trouble switching between towers or networks.
It can make your phone instantly kid-friendly. By putting your device in Airplane Mode before handing it over to kids, you can prevent them from visiting shady websites or making in-app purchases.
Despite the common practice, planes haven’t fallen out of the sky because someone left their device out of Airplane Mode. However, aviation operates with an abundance of caution, hence the rule.