The Department of the Air Force (DAF) said that it is focused on what mission systems a future tanker to succeed the Boeing [BA] KC-46A Pegasus tanker and the elder KC-135 will need. "While the DAF’s currently focused on a systems-based approach, we are not taking the development of the next-generation tanker off the table," the department said on Monday. Last week at the Air & Space Forces Association's (AFA) annual conference in National Harbor, Md., Air Force acquisition chief…