Estimating Potential Environmental Constraints on Aviation Growth

*† ‡ § ** †† We address environmental constraints on aviation growth in two steps. First, noise and emission models are linked with an existing model of the National Airspace System (NAS) . Second, we develop techniques to evaluate en vironmental constraints in terms similar to those used to evaluate capacity constraints. Combined, these steps provide the ability to include environmental considerations in quantitative, multi -dimensional system analysis of future NAS concepts. For the first step, the approach consists of : 1) standard FAA noise and emissions -inventory models are linked to Airspace Concept Evaluation System ( ACES ) simulation outputs; 2) appropriate modifications are made to ACES outputs to incorporate all information ne eded by the environmental models (e.g., specific airframe and engine data); 3) noise and emissions calculations are performed for all traffic and airports in the study area for each of several scenarios; and 4) the impacts of future scenarios are compared to the current NAS scenario. For the second step, the approach consists of: 1) identifying possible quantitative environmental goals in fuel efficiency and noise; 2) computing fuel efficiencies and noise a future scenario; and 3) estimating the traffic r eductions that would be necessary to meet the environmental goals. This paper also provides the results of end -to end, proof -of -concept runs of the integrated ACES and environmental modeling capability. These results demonstrate that if no changes are mad e to elements of the NAS, aviation growth is likely to be impeded by substantial environmental constraints . Pilot calculations of these constraints in terms of unsatisfied demand indicate that the environmental constraints may be similar in magnitude to c apacity constraints.