 A pilot was on board to supervise, so the demonstration was not entirely automated.It served as the basis for DARPA's Autonomous High-Altitude Refueling program which, in 2012, demonstrated the potential for fully autonomous aerial refueling of unmanned air vehicles.The final test involved modified RQ-4 drones flying in close formation less than 100 ft from a tanker, close enough for refueling to take place.