Car seat on plane?

We'll be flying to the US this spring when my little boy will be about 18 months old. I can't imagine that the regular seatbelt on the plane will be sufficient to keep him strapped in. I've heard that there are car seats that you can take  that fix to the airplane seat so you can strap the child in with the car seat harness. But I don't know if that's true or how it works. Certainly the car seat that we use in our car would be too big and hefty to lug around.
Thanks for any advice.
Lee

You'll need to contact the airline you'll be using to see if they offer child "carseats" to rent, as some airlines will provide them for a fee.  If you do use your own carseat it has to be FAA approved.  http://www.faa.gov/passengers/fly_children/crs/  Additionally, I believe if you intend to use a carseat on the plane you need to notify or make arrangements with your airline in advance to ensure you have a seat where you can fit the carseat in.  (I'm not too sure on that one though.)

Also, if you plan to use your UK carseat in the UK I believe it has to meet some kind of special approval, but I'm not positive what it is.  I know it's come up on the Parenting section, so you may want to repost your question there to ensure your child's safety if you do decide to take a carseat with you.

Good luck!

Thanks Teletabby, I'll copy my post to the parenting section.
Lee

Another thing to think about as well is when you get off the plane, if you are getting in a car you will need a car seat.
We bring ours on the flights so that we are sure to have the one that my son is comfortable in when we get in the rental, or in the in-laws car.

Masoncitychad, that's what I was thinking too. I can request a car seat with our rental car, but I'm not confident they'd actually have one available when we got there, or if they did what state it would be in. Safer I think to bring a car seat with us, so that's what we've decided to do.
Thanks

we always take our car seat as well..  Carry it in a bag and have it ready  for car journeys. ONly once did we  take it on board  the plane  and probabaly wouldn't do it again.. do they have  cots  for  your baby to sleep in?? 

azroomie - unfortunately he's now too big for the cots. When we went last year he was six months old and could use the cot, which was great as he slept most of the way and kept our hands and laps free. He's well over the weight limit now though. He's such a good car traveller that hopefully being in a car seat on the plane will keep him comfortable and happy (and sleepy!).

Brin,
We always just check ours at the gate as well.  We bring it right up like we are taking it on the plane and send it down with the stroller.  Otherwise they charge you for having too many bags.

Every airline I have flown in the last 9 years has let me check carseat without it counting towards luggage allowance. 

Anybody know what Easyjet's like with car seats (either being checked or checked at the gate)?  I looked up their policies online and found that I could check my carrycot and pushchair at the gate for free, but it didn't say anything about a car seat.  If I'm going to end up getting charged a bunch for a car seat, I'd rather rent one from the car rental place and not have to carry one around.  The car rental charge was fairly hefty for a week's use though.

Every airline I have flown in the last 9 years has let me check carseat without it counting towards luggage allowance. 

2 months ago, I was flying American Airlines and they tried to tell me it counted as 1 of my bags for the baggage alowance.