Whisper Aero secures $32 million in Series A financing

Whisper Aero, nascent developer of ultra low noise electric ducted fans, just announced $32 million in Series A funding. The round was led by Menlo Ventures, EVE Atlas, Capricorn’s Technology Impact Fund and Connor Capital with additional participation from Kindred Ventures, Abstract Ventures, Moving Capital, AeroX Ventures, Cosmos Ventures, Linse Capital and LaunchTN.

Whisper says it has developed a first of its kind electric ducted fan propulsion system that’s both quieter and more efficient than anything currently on the market. “If you want to get to scale with delivery drones or eVTOL air taxis, you better be really quiet,” Moore said. “You’ve got to be quiet enough that you’re not disruptive to those communities.”

The propulsion system has been designed such that can be scaled up or down for custom applications. Over the past two years, the company has designed, built and flown nine generations of this propulsor. They’ve settled on a product that both reduces the amplitude and that shifts the tonal profile of the noise to something significantly less cacophonous than traditional aircraft propulsion systems. The company says they’ve even been able to tune some of the frequencies into the ultrasonic, beyond what the human ear can detect.

Whisper plans to focus its initial commercialization efforts with the U.S. Department of Defense, an agency that they’ve already been working with for testing. Whisper has scored a handful of small government contracts from the DOD, including the Air Force Research Lab, to validate their propulsor.

The relevance of a quiet aircraft to the DOD is likely obvious. Whisper has validated that it can fly a 55-pound drone with its electric ducted fan at an altitude of 200 feet that is completely undetectable, at least by noise, from the ground. To put that in context, Moore said Boeing’s popular military drone, the Insitu ScanEagle, would need to fly at least 3,000 feet above to not be heard.

Whisper Aero is headquartered in Crossville, TN roughly halfway between Nashville and Knoxville, and emerged from “stealth mode” back in 2021 when it had announced over $7.5M USD in funding from investors, including Robert Downey Jr, Menlo Ventures, Lux Capital, and Kindred Ventures. The newly acquired $32 million will support the company’s rapid workforce and facility expansion efforts, alongside continued research and development testing.

Why it’s important: Noise and performance have long been tradeoffs in the design and manufacturing of propulsion systems. Whisper COO Ian Villa said the team has taken a first principles approach to propulsion and noise, starting with the most basic questions about how to turn electricity into thrust. Thus, the company has seemingly been able to minimize weight and noise while also producing a high-performance motor. Application of this technology in UAM aircraft has potential to hugely increase the likelihood of receiving buy-in from municipal regulatory agencies as well as general public acceptance.