They're allowed to be used but seen a lot of people fuss about how well they don't perform on flights? Not sure what that's about; can't confirm myself.
I think it's to do with the noise leakage. Because the AirPods don't form a tight seal and allow in some of the ambient noise.
So you'll probably hear some engine noise, crying babies, whinging passengers and so on.
I've not been on a flight yet, but I expect to hear some external noise when I do. Or be one of those irritating people who's music is so loud the person sitting next to you gets to enjoy it as much as you
and I'm not one of those people.