Integration of fuel conservative procedures in the high density terminal area

Fuel conservative procedures, including profile descents and decelerating approaches, can reduce fuel consumption significantly when executed as planned, but their effectiveness is strongly influenced by the Air Traffic Control (ATC) environment. Real-time pilot-and-controller-in-the-loop simulations have been used to establish the fuel savings potential as well as the operational problems of these procedures in the current ATC system. Simulation results have shown that fuel savings are realized under moderately heavy traffic conditions. In heavy traffic, high controller workload together with reduced fuel savings indicate that time-controlled (4D) guidance in the aircraft and computer-assisted scheduling may be necessary to realize the full potential of fuel conservative procedures. A computer-assisted technique, termed Constrained Position Shifting (CPS), is proposed to integrate these procedures into the future ATC system. CPS also increases capacity and reduces delay by accounting for the differences in aircraft sizes, capabilities and routes.