Distributed conflict management in en route airspace: human-in-the-loop results

NASA has developed a far-term air traffic management concept, termed distributed air/ground traffic management (DAG-TM). One component of DAG-TM, en route free maneuvering, allows properly trained flight crews of equipped "autonomous" aircraft to assume responsibility for separation from other autonomous aircraft and from instrument flight rules (IFR) aircraft. Ground-based air traffic controllers would continue to separate IFR traffic and issue flow management constraints to all aircraft. To examine en route free maneuvering operations, a human-in-the-loop experiment was jointly conducted in summer 2004 by the NASA Ames and Langley Research Centers. Test subject pilots used desktop flight simulators to resolve traffic conflicts in cruise and descent. The experimental airspace integrated both autonomous and IFR aircraft at varying traffic densities. This paper presents results from the en route free maneuvering experiment, focusing on airborne and ground-based conflict management during the cruise phase of flight, and the effects of increased traffic levels on the ability of pilots and air traffic controllers to perform this task. The results show that, in general, increases in autonomous traffic do not significantly impact conflict resolution performance. Together with previously-reported findings, these results continue to support the feasibility of the en route free maneuvering component of DAG-TM.