WWYD -- potential danger - someone going crazy on a plane?

In this case... yes I would step in. In many cases that weren't a physical threat, I would expect the crew to take care of it.

I have never had anything like this happen. I was stuck on a non-air conditioned airplane on a runway for way too long and saw a couple hundred people acting incredibly patient and good to each other.

And I stepped in on the T when someone was being racist.

Yes, I would jump in if there was a threat that the crew couldn't handle, but I'd have to see the threat. Someone ranting would put me on alert. Someone assaulting the crew or passengers or presenting an eminent threat would be required to go further IMO.

WWYD? What would Yeezy do?? Didn't think you were a Kanye West fan Linkat. I hope you're not considering voting for him come 2020.