That's too big for checked luggage too. Max dimensions for checked luggage is 62inches (L+H+W combined). That's remarkably small, 26x26x10." Impossible to fit a frame with normal 26 or 700c wheels inside unless it comes apart in the middle. And the box alone is 24 pounds, which is kind of ridiculous in my opinion. Especially when you consider the tools required to put a bike back together.
A box that big requires big time oversize charges, in which case you might as well use a big plastic case or a standard cardboard bike box. Or better off just ship it UPS/FedEx to you destination, it's cheaper domestically than flying with it.
There's a reason people pay big bucks for S+S couplings in bikes. They're awesome, and let you get bikes on plans without excess size baggage charges. I had my old Surly Crosscheck retrofitted with them and can't tell any difference besides being 6oz or so heavier.
http://urbanvelo.org/wordpress/wp-content/uploads/2008/01/sscrosscheck.jpg