The significant growth in air traffic over the past few decades has led to increased congestion at major airports. Departure metering strategies to mitigate congestion require good models of operations at the airport, as well as in the surrounding terminal airspace. Although runways have traditionally been considered the sole capacity bottleneck in the air transportation system, large airports can exhibit multiple points of congestion, both on the surface and in the terminal area. This paper presents an integrated surface-airspace model of aircraft departure operations from pushback to the final departure fix, when the flight leaves the terminal area. The airport surface is represented as a queuing network to capture congestion at multiple locations, such as ramp, taxiways, and runways. The terminal departure airspace is modeled considering various factors, such as runway configurations, standard departure procedures, weather, and en route traffic. The proposed modeling approach is illustrated for Charlotte Douglas International Airport, the test bed for NASA's Airspace Technology Demonstration 2 program. The model is evaluated on its ability to accurately predict various transit times, both on the surface and in the terminal area.
