Initial Evaluation of NextGen Air/Ground Operations with Ground-Based Automated Separation Assurance

NextGen air/ground operations with ground-based automated separation assurance have been initially evaluated with controllers and pilots in the loop at the NASA Ames Research Center. Nominal and off-nominal situations were investigated in a highly automated environment, under 2x and 3x traffic densities. The paper starts with a review of previous simulations on nominal operations, followed by a description of the underlying concept and the roles and responsibilities of controllers, pilots, and automation. The core of this paper discusses a simulation of air/ground operations, in which controllers and pilots were confronted with a challenging situation: Ground-based separation automation was managing the trajectories for all aircraft at 2x and 3x traffic densities without controller involvement. Routine and off-nominal events were carefully scripted that caused short-term conflicts, simulated emergency situations or required trajectory negotiations. It was found that the concept shows great promise to enabling the en route capacity increases targeted for NextGen. The medium-term conflict detection and resolution automation coupled with data link was able to solve over 98% of all conflicts during nominal operations, with a significantly higher success rate at 2x (>99 %) than at 3x. More than 95% of uplinked trajectories were acceptable to the flight crews. While controller workload was low in general and they were able to resolve over 75% of scripted off-nominal short-term conflicts, many issues were identified that need to be further addressed in the area of short-term conflict detection and resolution.