Most airlines allow you to use your devices during the flight as long as it's on airplane mode, I have never been on an airline that does not allow you to use your iPhone, but you should check with the airline first.
Quick Answer: Yes, AirPods work on planes and you can even use them during your flight. Airlines treat them no differently than wireless headphones. However, you should be aware of a few limitations. True wireless earbuds like Apple AirPods are great for work, home, and working out.