Some random thoughts:
* Give him good meals before each flight (not necessarily RIGHT before, though, because many kids get more active after they've eaten).
* Magnetic toys can help. We have one that has a magnetic board and lots of magnetic colored shapes. I'll send the name after work this evening. This one kept my kids pretty happy for an hour or more each on a long car trip over the summer. Magnetix are good, too (get sets with oddly shaped pieces).
* If you buy new toys just for the trip, do NOT allow him to play with them until you get on the plane.
* Highly engaging games that can be played alone or with others (YMMV on the definition of "highly engaging"): Some that work for us include Shut the Box, Camouflage/other ThinkFun games, Set, and YamSlam.
* New books!
* New Lego sets if he's a Lego-y kid.
* Carry lots of nutritious snacks
* Does he have a DS or similar handheld game? These toys can be extremely engaging. I think they're good things in moderation.
Hope that helps...
Val
