Originally Posted by
6rugrats
OP posted they are in the new business configuration with lie-flat seats. I don't believe you can fasten a car seat in these seats, they definately would not fit under a seat when reclined, and I am not sure where "to the side" would be.
IME, our Cosco Scenera fits in the (outboard) overhead bins of UA widebodies. I've also had good luck asking the FAs to store it in the closet.
While I've never personally tried to strap in a carseat into the new UA seats (as mentioned above, we use CARES in these seats), I don't see why a reasonable sized one wouldn't fit---in the worst case you can always drop the outer armrest and strap it in slightly off-center.