a function on a mobile phone or other electronic device that prevents it from connecting to the internet, used for safety when travelling in a plane

You can use your laptop on the plane in flight mode. 在飞机上，可以在飞行模式下使用笔记本电脑。

If your phone has flight mode then reading on planes is fine. 如果你的手机有飞行模式，在飞机上看手机是可以的。