I'm sorry, but if you can't control your kid to that level, you're doing children wrong

On the one hand, the eventual slap on the butt (Now supposedly prohibited world wide?) never hurt anyone and does wonders

On the other hand, if you have, say, a severely autistic child with special needs that sometimes just behaves like this, then I feel for you, my brother was, is like that, but I also do expect you to find ways to make it work somehow before you get into an airplane