Videos posted on social media showed Airbus UH-72A Lakotas with medevac markings and a Sikorsky UH-60 Black Hawk apparently using their rotor downwash to disperse crowds of protesters.

The successful test was performed June 3 at Redstone Arsenal in Alabama, and collected data that will be used to refine signal processing algorithms.

The District of Columbia National Guard is investigating “low-flying maneuvers” conducted by helicopter pilots over the city’s downtown June 1 after