I moved across the world to Oman with Alanna when she was 6 weeks old. 3 flights in a day, No problem during take off and landing! She was either asleep or feeding and didnt even notice. The only time she cried was while we were taxi'ing!
They didnt let me take her buggy on the plane but took it off me at the last minute at the plane door to go into baggage, and gave it back at the door after each flight.
Security is a right pain! Make sure all the liquidy stuff is quick to hand. And if you can.. get baby to sleep before you go through, they wont make you take her out of the buggy if she is sleeping!