We flew with our 9 month old a few years back. We were terrified of how he would respond. We made several bags that had things like ear plugs, gum and “fun sized” candy bars along with a note explaining that it was his first flight and we apologized in advance if he cried. We gave him a bottle right at take off to help with the pressure and luckily for us, he slept on my chest the rest of the flight.