Gluten Free menus are your friend. If they don't have a menu, I'm pretty sure they'll accommodate and make you a salad without croutons or something! Generally this is true for any chain restaurant you can find in an airport, like Unos, though you should avoid the bakery/breakfast places unless they have eggs (like Panera or Au Bon Pain). As a pilot, do you get fed during flights and does your airline offer gluten free meals?
Nuts are great for travel, but try not to exist off of them. I'm sure you can always find fruit in the airports too. I'll be interested to see what others suggest! I am sure Mark has some information about eating primal on the road.