Electric Flying Taxis Are Quietly Sneaking Up on Us (STEVEN ASHLEY, 6/14/24, Scientific American)
When the electric air taxi revolution arrives, you probably won’t it hear coming. A remarkable feature of an electric vertical takeoff and landing (eVTOL) aircraft is how quietly it flies, scarcely noticeable amid typical city traffic sounds. Unlike a helicopter, there’s no pounding, 90-decibel “thwop, thwop, thwop.” In contrast, eVTOL aircraft use multiple small propellers that spin half as fast as a chopper’s rotor—avoiding the annoying, low-frequency sound pulses created by the big whirling blades.
Electric motors, which are quieter than helicopters’ turbine engines, also help keep any racket to a minimum. “The latest air taxi designs, such as those from leading builders like Joby and Archer, deliver a 20- to 25-decibel reduction in noise levels compared to helicopters,” says Mark Moore, the trailblazing engineer who led the development of NASA’s X-57 Maxwell electric airplane. That means that eVTOLs could be four or five times less noisy to nearby listeners. Beyond offering quieter flights, these new machines should also be significantly safer, greener and cheaper to fly than helicopters. Moore maintains that electric air taxis are uniquely suited for what the aviation industry calls urban air mobility (UAM) services, enabling normally gridlocked travelers to “take advantage of the third dimension to escape the ant trails on the ground.”
More than two dozen major eVTOL builders have been founded in the past decade, and a few are nearing commercial certification from the U.S. Federal Aviation Administration or its European counterpart, the European Union Aviation Safety Agency (EASA).
The future always happens faster than you expect it to.