Cinderella - we've always used a car seat on the plane. Always felt safer. God forbid there's some heavy turbulance or even worse an accident a little kid could easily fly out of one of those seats. Anyway as long as the car seat has the 5 point harness it is fine to use. That's what they told us anyway. Booster seats are OK too again as long as it uses the harness.
Hope this helps - enjoy your trip!!
