We just came back from a trip with our 5 mo old where we had a 4.5 hour flight each way. Thankfully, he slept through most of the flights, both ways, but we did feed him when on landing. Take off isn't really a big deal but landings are where they usually have trouble. Not all babies and not all landings can cause this problem with their ears so it's really up to you as to wether or not to feed. I would just go with your gut, if baby is starting to fuss and is uncomfortable then offer something, breast or bottle, paci works as well although it is really the swallowing that helps the ears.
Another tip, if your baby is under two and is ticketed to sit on your lap for the flight, bring the infant car seat with you (if its the one for newborns) if there is no one sitting next to you, a lot of airlines with allow you to bring the car seat on board and you can buckle the baby up in that seat for no extra cost. That way you can a little bit more comfort for yourself and the babies are safely buckled in as well.
Have a great trip!
