Next summer we'll be taking our baby to Australia. Long flight from hell, and I've been dreading it for years. The baby will be one and a half at the time.
I've thought about it and thought about it some more, also not wanting to be that parent who has the screaming kid. But you know what I've decided? Kids have a right to travel too. When I used to fly a lot for my job and didn't have kids, sure, I'd wish babies wouldn't cry but I never blamed them for it. I felt sorry for the poor little things, what with the ear pressure and all of that.
So if anyone gets all up in your face, you tell them that your baby has as much right to travel as they do, and you're doing your best to keep her happy, so back off because complaining won't help and might make it worse.
In other words, have that look on your face that says, "DON'T F*** WITH ME" and nobody will bug you. Then, on the inside, stay as calm as you can so you don't transfer your anxieties to the baby. Remind yourself that it's only a few hours, which sucks, but it will end and then everything will be fine. Tell yourself over and over that you're not doing anything wrong. Give yourself some slack and your baby too...sure, if she was six and being a little screaming mimi, that'd be an issue but babies can't help it so there's no point in getting worked up over it.
All that being said, the tips I've been told are to not let the baby sleep in the airport so she'll be more likely to sleep on the plane, and to nurse her on board before take off to help with the ear pressure (and for the standard calming effects). And as others have said, have a new toy or two on hand to buy yourself some quiet time with those.
Good luck, and I hope you enjoy your destination. :)