The Efficient Descent Advisor: Technology Validation and Transition

Abstract

NASA recently completed the development and testing of the Efficient Descent Advisor (EDA) ‐ a trajectory-based tool for en route air traffic controllers that computes Optimized Profile Descent (OPD) solutions designed to minimize aircraft fuel consumption and associated carbon dioxide emissions while maximizing airspace throughput. EDA was developed and refined through a series of high fidelity Human-in-the-Loop (HITL) simulations, carried out in a three-year effort with the FAA and Boeing known as 3D-Path Arrival Management (3D-PAM). A final simulation was carried out to assess potential benefits using a prototype that reflected a culmination of previous design decisions. The simulation compared EDA against baseline operations in which controllers were provided with scheduling automation alone, representing metering operations today. For added fidelity, the simulation included models of trajectory prediction uncertainty. Results showed that EDA enabled a 92% improvement in the accuracy by which controllers delivered aircraft to the terminal airspace boundary in conformance with metering schedules. In addition, with EDA, controllers were able to accommodate overtake maneuvers en route without adjustments to the optimal arrival sequence. Furthermore, EDA was shown to reduce fuel consumption in transition airspace by 110 lbs per flight, averaged for all aircraft types and traffic scenarios, with substantially more fuel savings observed for busier traffic conditions and larger aircraft types. Reductions in controller workload were also observed along with a 60% reduction in the number of required maneuver instructions between controllers and pilots. Results from this simulation and previous experiments, together with prototype software and design specifications, were delivered to the FAA for transitioning EDA towards operational deployment.