M.S.
What airline are you travelling on? I went on air canada with my daughter in the snug and ride when she was an infant and it was fine. You don't use the base. Just pull the belt over and tighten into place. I plan on travelling again with my 5 week old son next week the same way. They would only let me take the seat on the flight if it wasn't full as I would not purchase a ticket for her. Good Luck to you.