We hate the food in most airports and even if a meal is served on flight, find it terrible. A long time ago, I started packing food. A great staple is a sandwich on french bread - the bread is sturdy and stands up okay against crushing. My favorite to bring on a plane is proscuitto and cheese; it's really satisfying without being messy. I'l also bring sliced apples and cheese, or grapes and cheese. (I find I need to eat protien with fruit or it makes my blood sugar too crazy.) Also, raisins/craisins and chocolate chips together are good; so are pistachios (especially for boredom). Sometimes I pack crackers, hard salami or braeseloa, and grape tomatoes. All of these things are easy to assemble and not too smelly.
A long time ago, Amanda Hesser wrote an arcticle about bringing food for travelling, it might be worth searching out on nytimes.com.
Let us know if you come up with any great combos!