747-400 stab tank is a fuel tank , not for c.g control as in airbus , hence none on freighters [up til now ?] . Only time i've put centre tank fuel in 332 was tankering from middle east to europe in the week or so that some routes had pax figures in single numbers after 9/11. Even then we only put a few tons in , so be interested to know if anyone using it properly on a regular basis. Think with that capacity its going to be an awesome tanker !!!!