Dachlostar,
We flew to Hawaii with Quinn when he was 14 mos, and we did a lot of other shorter trips before that. Arranging a flight at naptime or at night is the best thing to do, if you can. A sleeping baby is so much better! Quinn is also very very active. We got him a seat of his own on the Hawaii trip b/c we were using frequent flier miles. Though he technically didn't have to have one yet, it was soooo much better to have him strapped into his carseat (which we hauled along with us anyway since we were renting a car), since he's used to being relatively still in that and amusing himself. A good trick for having a seat for baby, if you're traveling with another adult and don't want to buy the baby a seat, is to reserve for the adults the window and the aisle in a 3-seat row. Unless the plane is very full, it's unlikely a single passenger will be stuck into the middle seat. If someone is, he/she will be more than happy to switch to the window rather than be stuck between two adults who are passing back and forth a baby! (Don't offer the person the aisle, as you'll want to get out to walk Yasin.)

We had lot of books, sock puppets, a small toy car, crayons, basically, anything little enough to pack. In addition to bringing lots of snacks (DON'T trust the airline to have appropriate foods), I'd also bring a lot of beverages. Airplane air is so dry, and drink service doesn't always coincide with when baby is thirsty. If you're still nursing, this is obviously easy; if not, try one of those sports bottles with the nozzle you can pull out and suck on. You can fill it with water, and a baby will get the hang of the drinking quite quickly, and it won't spoil like milk.

Also, flight attendants get bored on long flights in between meal service. Don't be afriad to take Yasin on walks in the aisles. We spent a very enjoyable 45 minutes hanging out at the "galley" area of the plane chatting to attendants when Quinn got too squirmy to stay in his seat. They had fun making faces at him, and he enjoyed the change of scenery. Good luck!
Annie