Just months after conducting its maiden flight with a 20-minute low hover and then demonstrating a speed of 80 knots, the advanced V-280 Valor tilt-rotor prototype has achieved an effective transition to cruise mode, hitting speeds up to 190 knots with its rotors smoothly transitioning between its hover and cruise configurations, according to announcement by Bell Helicopter on Tuesday — a major step forward for the experimental airframe that may end up replacing the UH-60 Black Hawk and AH-64 Apache helicopters in the U.S. Army's fleet.