I've traveled with kids from 4 months old up til 17 years old. (Still traveling with the 17 year old who doesn't even have to sit near me anymore, though he likes being nearby when it's an overseas flight, and I'm handing him water when all of a sudden he wakes up dry as a bone.)
I've traveled around others' kids. So I know the score.
The WORST trip I took was with drunk frat boys behind me. They were nasty and abusive to the attendants, and obnoxious to the point of one of them saying "Do you know who my father is? I'm going to report you and you're going to lose your job!" (She wouldn't serve them anymore alcohol.) I gave her my business card and told her that I'd be happy to talk to anyone at the airline if she wanted me to. Of course, he was full of hot air, since I never got a call.
Those were college guys - not toddlers. Yes, I've heard crying. I understand parents nowadays begging the kids to behave - they actually kick families off the plane if the kid can't calm down before takeoff. I'd bribe them too, if I were in their shoes and spent $1000 to fly...
My second worst flight was with a group of middle schoolers from another country who had "homestayed" in Canada for a month and were going home. They were 8 rows ahead of us, and the attendant wanted me and my sons to move up there with them so that the attendants had more room to spread out. My son came back when we were starting to move our stuff and told me where she was trying to move us. I had seen those kids running all over the concourse before getting on the plane. I told the attendant that I wasn't willing to sit with them - I'd never get any sleep. She was so mad at me for not moving that she barely gave us any help or service the whole overseas trip.
Turned out that the kids were crawling over the tops of their seats, making a tremendous amount of noise and bothering all the passengers around them. (No, there was no adult flying with them.) One of them threw an empty Coke can at her head. She apologized to me at the end of the trip when I told her I knew those kids were bad news because of what I witnessed in the airport. (Not that this helped me get any water during my flight...)
Anyway, my story is mostly for you to understand that PEOPLE behaving badly is just as bad as difficult children. Be prepared with toys, snacks, drinks for them to suck on (like juice boxes with a little straw) for take off and landing to help their ears. You could even go to watch planes take off before the first time, spend some time watching them take-off and land, get books from the library about flying on a plane, etc. "Sell" flying to them.
You'll be fine, LT!
Dawn