For me I found that at 5 months my children slept the entire flight, but they were both great sleepers. As you need to hold them during take off and landing there is no point getting them to sleep before plane takes off. WShen booking make sure that you tell the airline you are travelling with a baby and request the bassinet seat.
Just a few other things which may help:
- Due to ear pressure at take off and landing try to feed them as the swallowing helps them equalise.
- Bring a change of clothes for both of you just in case of any accidents (my son never throws up except on a plane)
- Bring your own food and water for baby. As the staff are busy I prefer to bring my own water (for atleast 2 feeds) and food, just because you have a baby doesn't mean you get priority.
- Make sure you have enough diapers and wipes for the plane (bring a few more diapers than the number you usually would use). Also depending on where you're going bring a few more in case you can't immediately access a place that seels diapers.
- Bring medication (just in case your child is sick after you arrive)
- If you use a baby carrier definitely use it
Finally remember it can get cold on the plane, especially for a sleeping baby so ensure that you bring some warm clothes and socks.
Good Luck & Enjoy.