According to the American Academy of Pediatrics, which recommend children 40 pounds at most, cradled in a car seat. This is one reason why many parents are now getting themselves into their own car seat travel bag. Besides, everyone knows that your child is more likely to exhibit good behavior if you are sitting in a comfortable chair and family. Sure you will find the light to travel without carrying a baby with you in the first round.
As for children using a forward and back seat with a harness is recommended that only with the certification label for use in motor vehicles and aircraft can be used in flight. The seat should ideally be less than 16 "wide to fit in the chair. As for ticket purchases abroad, you should review the label and make sure the seat has complied with the rules of the government abroad or at least in the United Nations.
Those who are not allowed would vests child, belly belts, straps and reinforcement. Apart from that, only children under 2 are allowed to use a car seat. For children over 2 years are required to use the standard seat belt. Children, moreover, that do not fit in the seat harness, use seat belts in place. The aircraft seat belt fit the child can also set more than a motor vehicle.