My guess is that the carry on policy varies from airline to airline and even plane to plane within an airline depending on the size and type of the plane. Different airports may even enforce their own policies as you attempt to get through their TSA screening.
I'd at least call the airline in advance to see what their policy is and perhaps print out a copy of it to take with you in case a gate agent should happen to challenge you.
I have come to the conclusion that people who respond to forum posts with "tl;dnr" should really be writing "add;dnr".
Last edited by beernutz : 11-14-2012 at 08:13 AM.