Originally Posted by
username
.... In that case, should UA ban it?
Airlines are required to accept any FAA approved child restraint system which includes certain aft/ rear-facing child seats.
https://www.faa.gov/documentLibrary/...AC_120-87C.pdf
10.f Operators Prohibiting CRS Use. No aircraft operator may prohibit a child from using an approved CRS when the parent/guardian purchases a seat for the child. If an approved CRS, for which a ticket has been purchased, does not fit in a particular seat on the aircraft, the aircraft operator has the responsibility to accommodate the CRS in another seat in the same class of service.
The FAA does require these be placed in window seats, not blocking anyone/s exit in an emergency.