I've never been pelted with cookies

Seriously, if you keep your kids happy, occupied; ensure they don't kick the seat in front of them, throw their food, drink, toy, etc. I think you'll be fine. I enforced a plane, airline club, hotel executive club et al as "fuss free zones". She's not allowed to act up, use anything but an indoor voice, etc. if she wants to stay there. It's worked for us.

Don't dread it; relax and enjoy the trip. We've stopped bringing the car seat for baglady jr. and instead bought her a pillow (she picked it out and carries it) that helps her to sleep since we have some late night flights on occasion. I bring her favorite snacks; a new toy or activity; her leapster game system (with headphones); dvd player; dvds (again, with headphones); an art kit; some little toys, a blanket and whatever her favorite plush toy is of the day. Also, she likes to have her shoes and socks off in order to get comfy; so I do that after we're settled in. It works for us. Enjoy your trip and if nothing else; don't stress