Most US Airlines state dimensions as 22x14x9, yet if you go on the websites of various luggage manufacturers, bag sizes which they claim have been tested, show outward dimensions bigger than 22". For instance the TravelPro Platinum Elite 21 has an exterior dimension of 23.5 which is seemingly over the sizing allowed. Sam is true for many other cases and brands. Not sure how to think about this as I absolutely want a case that will almost never get challenged.