Unfortunately, once a panic attack has reached the level we see in the video, it's very difficult to stop it. She's beyond the point of reason and her brain is so overwhelmed with "dope" (meaning that her parasympathetic nervous system is chemically overwhelmed) that she simply cannot process logically. So she literally cannot control what is happening to her. She would likely need to be medicated or removed from the situation.

The worst thing one could do in this case would be to tell her to calm down, because that invalidates what's happening and will cause her to feel even more isolated.

Flying is not a trigger for me, thankfully. A year or so back, however, a young man was having a panic attack on a flight - we had already left the gate - and so I switched seats with the person next to him so that I could try to help. He wasn't at the level we see in this video, but he was getting there. I sat next to him and put my hand on his shoulder and explained what was happening to him. We who suffer from this ailment understand the causes, however, that all goes out the window when panic occurs. We know why we feel the way we do, but when it starts, we don't believe it anymore. I told him that I understood what he was feeling and explained that I shared the condition. I told him that his brain was telling him lies and that the fear wasn't real. I told him that he is overwhelmed, chemically, and that he needed to focus on letting it pass, because it would; that that his brain would begin to absorb the rush of epinephrine. "I'll wait it out with you", I said. This gave him a target to focus on and we counted out long breaths. Thankfully, it worked, and he was able to overcome it.

I'm not a pro at this, I don't think anyone is, but I think the trick is honesty. Our brains lie to us, and we need to be reminded of that. Explaining the process also seems to help, because it gives us hope that it will soon end, naturally. It's a hard thing to deal with and most people don't appreciate that. It isn't a matter of "get your shit together", because that's physiology impossible.