"Blade-mounted flap control for BVI noise reduction proof-of-concept test"@en . . . . . . . . . . . . . . . . . . . "Interactional aerodynamics." . . "Aeroacoustics." . . "Wind tunnel tests." . . "Blade-vortex interaction." . . "Pressure distribution." . . . . "Flaps (Control surfaces)" . . "Aircraft control." . . "Active control." . . "Helicopters." . . "Noise reduction." . .