[American Institute of Aeronautics and Astronautics 12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference and 14th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference - Indianapolis, Indiana ()] 12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference and 14th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference - Fleet Assessment of Fuel Burn and NOx Emissions for NASA Environmentally Responsible Aviation (ERA) Technologies and Concepts