Resumen de Silence of the drones: how to hush the humming
Drones tend to live up to their name, emitting a low buzz that may be a problem if fleets of delivery drones start operating in urban airspace. But a team from the National Aeronautics and Space Administration (NASA) has now developed a way to silence that annoying noise. The GL-10 is the latest in a series of prototypes from NASAs Langley Research Center in Hampton VA. It is made from carbon fibre and has a wingspan of 3 meters. But its most unusual feature is the large number of engine, with eight on the wings and another two on the tail. One aim at this is to generate efficient electric propulsion, but the project also solves the problem of aircraft noise: several small motors are quieter than a few large ones. The GL-10 uses Leading Edge Asynchronous Propeller technology, which prevents the sound from the propellers combining into one loud noise or harmonic.
