I just did another quick check with Delta (most airlines are probably the same) - the maximum size for luggage is 62" - add the Length x Width x Height or else you have to pay oversize baggage charges. Max weight is 50 lbs and as an OP said, it is much easier to creep up to that weight quickly the larger the suitcase. I decided to double check because I remember last year I was going to use my 26" Air Canada Brand suitcase and when I measured everything it was 62 3/4" including the wheels so I didn't want to chance it....I'd really, really double check the 29" to make sure....(luggage stores will tell you ANYTHING you want to hear about airline regulations to sell them but when you get to the airport, you don't want a surprise