This is the backpack I have and use all the time, but I have never tried to take it on a plane. I'm wondering if anyone has ever flown with this bag. My initial thought was that it's too big to be used as a carry-on bag. Afer some reasearch, and measuring, it appears that if I remove the side pouches, it will meet United Airlines size limit of 45" (L+W+D). I would hate to get to the airport thinking I'm going to be able to cary this bag on with me, only to find out when I get there that I have to check it.