In an exercise entitled Falcon Virgo 15-13, NORAD flew four ultralight aircraft, including gyrocopters, in the airspace around Washington, DC, this past Sunday. Falcon Virgo is a long-running series of exercises to test interception and airplane identification techniques; there was one, Falcon-Virgo 15-07, conducted less than two weeks before Hughes' flight, with F-16s, a Gulfstream jet, and Coast Guard helicopters flying in the area. Radar is very good at detecting large aircraft. But it has problems with smaller vehicles, which sometimes appear like birds or balloons. this was the case for Hughes, who showed up on FAA radar, but just as a small blip. At a congressional hearing about the gyrocopter, FAA Director Michael P. Huerta and the U.S. Navy's Admiral Bill Gortney testified that the slow, low, and irregular flight of the gyrocopter appeared as either a weather system or a flock of birds.