Hi! My son is high functioning autism (auspergers), and we fly A LOT (as you can tell from my user name

Anyhow, he'll be 5 the end of may, and here's our routine: I love Benedryl! He usually takes a nice nap for us! We purchased a small DVD player to take along with his favorite movies (this is also nice for the hotel to give him continuity/familiarity). Since the battery is only good for 2 hours, we usually hold off pulling this out until close to fussing. We have him help pack his back pack with favorites like hot wheels, couple books, blankie (very soothing for him), etc. We have his water bottle along and his snacks. He has a very hard time with food, so I always pack sandwich, etc. that I know he'll eat. Plus the continuity of same "Mom" food, water bottle, etc. is comforting. We do let him pick what he wants from the beverage cart as a treat, and he looks forward to that. It also seems that he does better if the family splits up. Usually Dad takes one son, Mom takes the other, and we sit in different sections. This gives ds the one-on-one attention, so we don't miss anything he may be feeling. We've also experienced melt downs, and you just get through them the best you can, with as much grace as possible! Ha! The only other thing we've run into is if we are sitting by the engines, it is often too loud for him. We have noise-reducing ear phones he wears because the plugs are too big and won't stay in his ear canal. I'm sure a portable cd player would work too with some soothing music, or your child's favorites.
We'll be flying Seattle - Orlando in May, so will have a long direct flight ahead of us! My 4 must haves: benedryl, dvd, blankie, his food! Everything else we can work around.
Good Luck! Pam