Originally Posted by
corporate-wage-slave
And the allowance is 56 x 45 x 25cm. Though I personally think that you may get away with this, particularly at JFK, nevertheless the risk is there and with something so massive, well that's the point of checked luggage and you would be a sitting target if they ping anyone. It will get through the scanners since the one critical size there, the second biggest measurement is the lay flat height and as it happens you are below the maxima on that.
I am not sure this is right about the scanners, since in some airports the bag has to fit into a tray and cant be sent loose. I have an idea that is the position in T5 (at least in the First Wing).