I upgraded with my cat when I moved here. It was some years ago so I don't remember how I upgraded--but it wasn't an issue. I do remember I wanted an aisle, but there was only the bulkhead in first, so I had to take a window in row 2. My cat did make some noise, but you could barely hear it with the engine going. No one else could hear, not even the guy next to me. I did give him a sedative that my vet gave me. Also, you have to carry him/her through security and the carrier goes through xray. Mine held on to me with his nails he was so thrilled. Good luck!