Re: Airline/Travel car seat situation..
Your 4 year old might fit in the plane seatbelt alone. I think the CARES should work for the 3 year old but keep in mind that it doesn't nothing to help the fit of the lap belt. I can't see an average sized 3 year old NOT fitting in the Triumph. We have those as program seats so I see them a lot.
CPST-I and SAHM to DS