  Through an aviation emissions estimation tool that is both
publicly-accessible and comprehensive, researchers, planners, and community
advocates can help shape a more sustainable and equitable U.S. air
transportation system. To this end, we develop an open-source, data-driven
methodology to calculate the system-wide emissions of the U.S. domestic civil
aviation industry. This process utilizes and integrates six different public
datasets provided by the Bureau of Transportation Statistics (BTS), the Federal
Aviation Agency (FAA), EUROCONTROL, and the International Civil Aviation
Organization (ICAO). At the individual flight level, our approach examines the
specific aircraft type, equipped engine, and time in stage of flight to produce
a more granular estimate than competing approaches. Enabled by our methodology,
we then calculate system-wide emissions, considering four different greenhouse
gases (CO2, NOx, CO, HC) during the Landing, Take-off (LTO) and Climb, Cruise,
and Descent (CCD) flight cycles. Our results elucidate that emissions on a
particular route can vary significantly due to aircraft and engine choice, and
that emission rates differ significantly from airline to airline. We also find
that CO2 alone is not a sufficient proxy for emissions, as NOx, when converted
to its CO2-equivalency, exceeds CO2 during both LTO and CCD.
