How do you survive 16 hours flight?

Answer 1

The greatest danger of a 16 hour flight is from impaired blood circulation in your legs, from sitting that long, which can cause an embolism. Try to periodically exercise your legs. Other than that, sleep when you can, and perhaps bring a good book with you. The person sitting next to you on the plane may or may not be worth talking to, so you can't count on that.