Always follow the crew's instructions, for your own safety.
Flight attendants categorize every passenger as “helper, neutral, or potential problem” within 3 seconds ...
Flight attendants have a unique opportunity to learn the best travel practices when it comes to air travel. Naturally, many have a few tricks up their sleeves for making flights more enjoyable, ...
They can decide whether you make it to your destination or not, but their resources are limited.
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Why Do Flight Attendants Sit on Their Hands?

This unusual position is part of the cabin crew’s safety training.