I thought it was weird though at petsmart they had a lot of "airline" type bags but they were all to big for the flight I was going to take. They say "approved for most major airlines" but I checked jetblue, virgin, and american and they all have 8-9" at their upper limit of hight. My poor big yorkie would hate being squished like that. I would like to know which airlines take these "approved" bags- some are as high as 11" but I couldnt find a single airline that said thier bag could be that big.