"A risk-minimizing algorithm was used to compute and command a safe trajectory continuously throughout 23 miles of rugged terrain at an average speed of 40 knots. No prior knowledge of the terrain was used."
Source: Matthew Whalley, the Autonomous Rotorcraft Project lead, commenting on a November 5th flight over the skies east of San Jose, CA, where a Black Hawk helicopter was flown autonomously. There were pilots aboard the aircraft, but all maneuvers during this flight were being conducted autonomously.