They actually solved that. Watch Mark Robers video at 13m50s: https://www.youtube.com/watch?v=DOWDNBu9DkU&t=830s https://www.youtube.com/watch?v=DOWDNBu9DkU&t=8

They actually solved that. Watch Mark Robers video at 13m50s: https://www.youtube.com/watch?v=DOWDNBu9DkU&t=830s https://www.youtube.com/watch?v=DOWDNBu9DkU&t=830s However this FAA approval is apparently for the Gen1 fixed wing plane (which is quieter than a drone anyway). Their Gen2 "drone" design is barely audible.