The Future of Advanced Air Mobility

Whisper Aero Set to Reveal Details About Its Ultra-Quiet Propulsion System

Whisper Aero, a Tennessee-based tech start-up developing what it claims will be the quietest electric propulsion system on the market, is getting ready to finally offer the public a taste of its secret sauce. 

Having quietly worked on its propulsion technology since February 2021, the company has yet to reveal any details about its product, such as the expected power output and noise levels. Now the company is almost ready to reveal some of its secrets. Ian Villa, Whisper Aero’s COO and chief product officer, told FutureFlight that the company will be revealing new details about its propulsors “toward the end of March or early April.”

Although he did not share any specifics, Villa explained that Whisper Aero plans to offer multiple different models of its propulsion system with different levels of power output. And the company isn’t just sticking to aerospace applications. The quiet and efficient thrust technology that Whisper Aero is developing could also be scaled for smaller products on the ground, such as leaf blowers, HVAC systems, stove top fans, and bathroom fans, Villa explained. “We’re in the business of moving air,” he said. 

On the aerospace side, Whisper Aero is focused on delivering quieter and more efficient thrust for drones and electric fixed-wing aircraft. “We have developed this new technology that scales for drones, for jets, and maybe sometime in the future—but not anytime soon—eVTOL propulsion,” Villa said during a recent media briefing on regional air mobility organized by consultants McKinsey & Company.

While Villa declined to say exactly how quiet Whisper Aero’s propulsion system is, he did say that it’s around 20 decibels quieter than “even the quietest electric things out there.” He added that the U.S. Department of Defense (DoD), which has awarded the company with six grants so far, has independently verified that Whisper Aero’s propulsor is the quietest compared to other electric propulsion systems.

Whisper Aero's engineering team.
Whisper Aero's engineering team has so far revealed next-to-nothing about its new electric propulsion system. (Image: Whisper Aero)

To test its new technology, Whisper Aero built a 55-pound (25 kg) demonstrator drone and equipped it with the ultra-quiet propulsion system. Villa noted that Whisper Aero is not in the business of developing any airframes and that the drone is only being used to test the new propulsors. So far the company has tested nine iterations of its technology, and “each time we sort of add a layer of new innovation,” Villa said. “That flying testbed allows us to test all those technologies before we're ready to stick them into a real product.”

Under the DoD’s classification scheme for uncrewed aerial systems (UAS), Whisper Aero’s propulsion system has been tested on drones categorized as group 2. The groups are ranked from 1 to 5 based on their capabilities, with group 5 designating the fastest drones with the heaviest maximum takeoff weight. “The tech scales, so it also could work on a group 1 application that we've been developing, and it goes larger. So we've been paid by the Air Force to see just how large it goes,” Villa said, adding that Whisper Aero is now working on a group 3 propulsor.

Villa did not say exactly what kind of data, if any, might be released when the company reveals more about its work this spring. And whether it will reveal the full recipe of its secret sauce for the ultra-quiet propulsion system is yet to be seen. All the company's co-founder would say about Whisper Aero’s propulsion system is that the technology relies on basic physics principles. “It goes back to first principles. A lot of people forget to look at first principles,” he said. 

“There are a lot of benefits to electric motors and what you can do with distributed electric propulsion that people aren't thinking about” in the aviation industry, he said. “They're just thinking, ‘How do I get this into flight as quickly as possible?’ So we really see ourselves as moving into the second generation—this new generation of distributed electric propulsion. It's cleaner, it's quieter, and it's more efficient.”