Rockwell Collins was awarded a $64.6 million contract modification to provide Global Air Traffic Management (GATM) systems for the U.S. Air Force’s C/KC-135 tanker program. The GATM equipment ensures the aircraft meets communication, navigation, surveillance and air traffic management requirements. Total value of the contract now exceeds $555 million, Rockwell Collins, Cedar Rapids, Iowa, said. As of March, Rockwell Collins said it delivered 229 C/KC-135 production aircraft equipped with GATM technology.