التاكسي الطائر: Whisper Aero يحافظ على مستويات الضوضاء منخفضة

BLOOMBERG

Endless encounters with bee swarms.

This is the cacophonous scenario that investors may be rushing towards as they pour heroic sums of money into companies developing ever-better drones and their larger cousins, vertical take-off and landing passenger vehicles. Because, while the underlying technology behind these machines has advanced at a breakneck pace, the simple fact remains that, big or small, these aircraft produce a lot of noise, and little has been done to mitigate it. Imagine having 10,000 flying taxis overhead if a drone has ruined your peaceful day at the beach.

Whisper Aero, a startup that is revealing its plans for the first time, believes it is well on its way to solving the noise problem. Mark Moore, a former National Aeronautics and Space Administration engineer turned executive within Uber Technologies' once thriving flying vehicle division, founded the company in mid-2020. Moore is convinced that Whisper has hit on a new "thruster" design that will result in consumer drones all the way up to large passenger vehicles blending into the background noise of a city as they fly. While he declines to reveal what he has come up with in full detail due to intellectual property protection concerns, Moore is convinced that Whisper has hit on a new "thruster" design that will result in consumer drones all the way up to large passenger vehicles blending into the background noise of a

"Half of the people think drones are cool, and half of them are irritated," Moore says. "They're irritated because there's a really annoying noise source that shouldn't be there. It makes people feel very uneasy because it sounds like a flying Cuisinart. You can't annoy or scare people into believing that more and more of these things will appear if you want them to believe it."

Few, if any, people would be better suited to try to solve such a long-standing problem in this field. Moore worked for NASA's research groups for thirty years, developing cutting-edge designs for drones and electric aircraft. In 2010, he published a paper on the possibilities of all-electric aircraft that could take off and land vertically, and his research sparked interest in the so-called eVTOL machines that are now being pursued by dozens of start-ups. Moore joined Uber Elevate in 2017 to assist Uber in creating a massive fleet of flying vehicles that could soar above traffic.

However, as the pandemic spread, Uber abandoned its sci-fi plans and sold its Elevate technology to Joby Aviation, a startup backed by Toyota and recently valued at $6.6 billion that some regard as the most promising eVTOL contender. Rather than staying at Joby, Moore decided to pursue ideas he'd had for five years about how to make quieter vehicles. He used some of his Uber money to purchase a run-down resort in Crossville, Tennessee, and converted it into Whisper's secluded headquarters and R&D compound. Moore explains, "The bank was foreclosing on it, and I got a steal of a deal." "It's 16 acres with a lake and a beautiful beach, and it's right next to a great little airport."

According to Moore's count, approximately 400 companies are attempting to develop eVTOL aircraft. Many of these vehicles are built by hobbyists and small teams, while a few dozen companies have received significant funding to go after the market. The majority of the early versions of these vehicles resemble one another. They're basically small planes with electric motors that drive four to twelve propellers. The big race right now is to build working prototypes and get the vehicles certified as safe to fly by regulators.

Moore believes that the noise generated by the first wave of eVTOL vehicles will limit their success. The aircraft, while quieter than helicopters, still produce a swarm of bee-like buzz. Moore believes that part of the problem stems from companies' refusal to deal with noise in their rush to get aircraft to market. "Everyone is following the path of least resistance," he claims.

While Moore was hesitant to describe Whisper's technology, he did say that the company is developing a new type of thruster design. This includes a fresh perspective on propellers, motors, control systems, and how all of these components fit into the airframe of a vehicle. As part of a contract with the Air Force, Whisper has been testing its technology on drones. Engineers take their prototypes to the tennis and basketball courts at the resort and surround them with microphones to measure the noise signature. So far, the technology has worked well, with the devices' hum blending into the background. "The industry is currently in the propeller age," Moore says. "We'll bring it into the age of the electric jet."

Whisper will reveal more about its technology in the coming months, according to Moore, as its patents are approved. The company intends to begin selling its first products by 2023, with the expectation that they will be purchased by drone manufacturers. It then intends to sell the thrusters to eVTOL manufacturers, which will be a difficult task. Because of the new technology, the companies will almost certainly need to redesign their aircraft and possibly re-certify them with regulators. Whisper believes the technology will eventually find its way into other industries.

Seongkyu Lee, an associate professor of mechanical and aerospace engineering at the University of California, Davis, is skeptical of a quick breakthrough in noise reduction. Drones and eVTOL aircraft emit a type of higher frequency noise known as broadband noise, which is particularly irritating to humans. "The next steps in noise reduction will be incremental," says Lee. "I doubt we'll be able to achieve a 10 or 20 decibel reduction in a single shot. However, if we want to put these things in neighborhoods, we must figure out how to make them quieter."

Whisper has so far raised $7.5 million from investors including Robert Downey Jr.'s FootPrint Coalition Ventures. "It is a problem to create unchecked noise pollution for the sake of electric aviation's vital future," Downey said in a statement. "The future must be as thoughtful as it is compelling." Because Iron Man, of course, wants his air taxis to be quiet.

Menlo Ventures, Lux Capital, and Kindred Ventures are among the other investors. Shawn Carolan, a partner at Menlo Ventures, admits that Whisper faces many "hard engineering problems" ahead, but believes that if the company's products work as advertised, nearly every drone and eVTOL company will flock to it. "Every now and then, you see one of these things that I refer to as technological inevitabilities," he says. "This has the potential to drastically change the world."