Worry about the plane going down because of it? No, not at all -- the plane and the pilots can handle a heck of a lot.

Worry about me or mine getting injured? Yes. I've seen bad scalds, bruises and goose-eggs, and even one or two broken noses. Lots of expensive clothing &/or laptops ruined, and smells that are sheer torture. While none of it is likely to kill us, it can sure ruin the trip, and who wants that?

Keep that seatbelt on whenever possible, don't eat too much dairy before you fly, and skip the coffee if the pilot says anything about possible rough air.