The goals of the Federal Aviation Administration’s (FAA) Next Generation Air Transportation System (NextGen) include improved safety, increased capacity, increased efficiency, and reduced environmental impact. The FAA has developed 46 mid-term Operational Improvements (OIs) to facilitate initial realization of these benefits in the 2015 – 2018 timeframe. These OIs describe changes in technologies, policies and procedures from current-day air and ground operations designed to mitigate safety, capacity, efficiency, and environmental issues. The main goal of this project was to investigate how thoroughly threats to safety present in today’s operations are addressed by the OIs. These threats, without mitigation, could remain threats in the mid-term, potentially compromising the intended NextGen safety benefits. To address this concern, we extracted threats to safety from 200 Aviation Safety Reporting System incident reports filed by tower air traffic controllers over a five-year period. We then evaluated whether these threats are addressed by the mid-term OIs