"We are taking our 18-month-old son overseas soon. I've readthrough your archives and feel relatively equipped to deal with his jet lag and the unfamiliarity of a new place, once we get there. But the trip itself will be brutal. It involves 2 red-eyes in a row: a too-short one at midnight to get from our home in the west to New York; five hours in the airport, and then an 11 hour flight which leaves at 11 am and lands at 5 am the next day in the new time zone. Then we have to tough it out until we can sleep that night.
How do I help my son get through this flight? We will try to get him to sleep early beforehand, so that he gets some rest before the airport and the first red-eye. During the layover we will run around and stretch our legs as much as we possibly can. But 11 hours on a plane, including both some daytime and a night's rest? I am planning to bring his PJs and bedtime books on the plane so that we can try to replicate our going-to-sleep routine mid-flight. Various pediatrician and parent types have suggested Benadryl, but I am reluctant to give him unnecessary medication. He still nurses avidly, so that's a help. He has flown plenty of times before, but never for more than 5 hours at a time. Anything you and your readers can suggest would be greatly, greatly appreciated."
The good news is that this will be the worst trip of your life, travel-wise. So that's something.
It sounds like you've really thought out the whole thing and have identified the trouble spot. The 5-hour flight probably won't be a problem, since he'll probably sleep for an hour or so. And then the layover in the airport should be doable, with all the runningrunningrunning he'll do. (Although with that much time it might actually be worth it to research someplace close to the airport and go outside, so he can get some sunshine and fresh air while he runs. If you post which airport you'll be at in the comments the New Yorkers in the crowd will help you find a park or something close by.)
It's really that 11-hour flight that's going to kill you. If you've got as many activities as you can schlep (including a bunch of small new ones he's never seen before), and you can replicate the bedtime routine, that's probably as good as it's going to get. Try to stuff him full of food to make him sleepy when it's time, and hope you get good flight attendants. (I find that flight attendants make or break the flight, much like the nurses in the hospital make or break a labor and delivery.)
My only opinion on the Benadryl is that you MUST give it a trial run before you use it on a plane, because it makes some kids zonk out but it makes other kids hopped up and unable to calm down for anything. So if you're thinking of trying it, make sure you know if it works the way you want it to, or you could make things 100 times worse for yourself (and everyone else on the flight). I don't have a problem with giving it in theory, but can also understand why you wouldn't want to.
Who regularly travels that far with kids? I know there are some regular readers who fly to India and the Middle East from the US. I've never flown more than 5 hours with my kids, so am basically useless with the detailed practical tips. Is there something really obvious that I haven't talked about?