I would check it at the gate if the baby won't have a seat. When my gradfather passed away in July 2002, my cousin, my 6 m.o. , and I flew stand-by to the funeral. Because we were stand-by, we were searched at every plane change between OKC and Seattle. At one of our screenings, they asked me if I wanted to check the car seat. I said 'yes' and they promptly lost it. It was eventually recovered at our final destination, but the thought of using one of their "loaner" carseats wasn't that appealing to me since they were for older kids. So, I hung onto it for dear life on the trip home and only surrendered it to flight attendants who always knew where it was once the plane landed.