Which AFB? Is it high altitude? What is the temp.? Is it very hot (above 90F)? Is the KC
-135R at it's MGTOW of 322,500lbs? Any of these factors will effect take off performance. Today, the KC
-135R is considered a very good performer, with performance very similar to the B-757-200, even though it is more than 52,000lbs heavier when both are at MGTOW (B-757-200 MGTOW is 270,000lbs).