The advice here is based on my experience
of taking several long haul flights with babies and small children in the years
1997-2004. After the children were over the age of 6, it became much better because
they could read, play cards, and play with the computer games the airlines
install on the backs of seats.
Bring a sling/baby carrier.
We did not use car seats, so I would strap the infant or toddler into the baby carrier (front) and then strap myself in, during take off and landing. I would also walk a lot or stand a lot w/ the baby or toddler to soothe them. I joke that I've walked across the Pacific several times.Breatsfeed or give bottle during take-off and landingIt's also more convenient to go to the toilet yourself if the baby is in a sling or baby carrier. But, remember to cover baby's ears during the flush, because it's very loud and scary sounding for them.
This is important to help keep the baby's ears from clogging due to the pressure changes. Older children can be given gum to chew or follow other techniques like blowing their noses.
What to have in your carry-on bag
I usually changed the babies on the floor in the back of the cabin. If my row wasn't crowded and it was just pee, I would change them in my seat. I didn't like the changing shelfs inside the plane's toilets because they were small and it was often hard to know which had them and which didn't.Consider sedatives.
For several trips, I asked our pediatrician to give me something that would mellow the kids a bit for the flight. He gave us a decongestant (so it helped w/ the ears) that also made themn drowsy. I also used it after we arrive to help the kids adjust to the 12 hour time difference.. If you are considering using a sedative - ask your child's doctor about it.Accept helpIMPORTANT: If decide to use a drug, try the sedative on the baby at home a few days or a week before you leave. This way if there is an adverse reaction (maybe that medicine makes your baby more hyper) you will know about it.
I would not bother with a sedative for a flight of less than 6 hours.
When I flew with my son when he was 7 months old, I flew with him as a "lap baby" on a full flight. On the Hong Kong to San Francisco leg of the journey, there was a grand-parenty couple next to me who enjoyed playing with him. They held him while I ate my meal, and the husband took him for some walks around the plane, it really helped. When I flew back to HK the flight from LA (I had flown Boston->San Francisco-LA-Hong Kong that time) was also full and I sat next to a nice single lady who also held the baby while I ate.Practice Self-Help
I try to get things ready for myself, because I don't expect much immediate help from the flight attendants. They are very busy, so I try to plan ahead (e.g. asking for the flight attendant to fill the thermos when things are not busy).Timing Meals
If you are flying with another adult to help you, ask your flight attendant to serve yourmeals separately, so one can eat while the other takes care of the baby.Endure and Accept Suffering
In all my flights there's been moments (or even hours) that were very hard ("sheer hell") but most of it was OK. I also remind myself of how it is better than other experiences I have had: labor for instance, or an 8 hour trip on a Chinese bus that turned into a 17 hour long epic journey; or the time that the 1 hour trip on the Trailways never happened because the bus broke down and I had to spend the whole night on a COLD broken bus...Keep CalmThings do get better. I was amazed last year when I traveled with my kids who are now 5 and 3. I was actually able to read and finish a novel on the flight, for the first time in 5 years!
Try to think about what you would need to pack for your baby if you were going to spend a long day out shopping or visiting relatives in your own town. The supplies you need are not that different.My Experience
I've done 24-hour trips (this includs time spent waiting to change planes) from Hong Kong to Boston, Mass. and back again with my kids at various ages: