My baby Larrivee is just a bit bigger then the baby Taylor, and there were no problems with carrying it on-board.
Moonchild and Rick have a point about carrying full sized guitars on-board, but chances are pretty good that you will be forced to make that plea! That is, while you may well be able to fit a full sized guitar case in the overhead, I suspect on most airlines, you would be asked/forced to check it. You could make the arguement, and you could win - but you might not. When I transport my big guitars, I'd rather not worry about the arguement; I'd rather check it, insure it, and pick it up at the end of my flight. And by the way, I'd never check one I couldn't replace if I had to.
I think you'll find your baby Taylor travels well!