Pentagon leaders are poised to approve the requirements for the Air Force's new aerial refueling tanker, a set of performance guidelines that will have a huge effect on the high-stakes competition to build 179 aircraft in a deal expected to be worth tens of billions of dollars. On Nov. 28, the Joint Requirements Oversight Council, chaired by Adm. Edmund Giambastiani, the vice chairman of the Joint Chiefs of Staff, agreed that the aircraft selected to replace the aging fleet of...