New York to Paris in Under Four Hours? Inside the Effort to Build the Next Concorde

When the Concorde was grounded in 2003, done in by strained economics  and a fiery crash on a Paris runway, it appeared to be the end of the line for supersonic travel. Nothing emerged to replace it. In fact, the speed of air travel moved in the opposite direction, with many routes getting slower in recent years as congestion and air-traffic control inefficiencies jammed up the skies.  

A former Amazon software engineer named Blake Scholl founded a company to change this. A decade ago, he launched Boom Supersonic, betting that his Denver-based startup could tap in to the allure of ultrafast travel—a desire that has never quite been extinguished despite the financial and practical challenges that ended the Concorde’s nearly 30-year run. Scholl sees a world where round-trip trans-Atlantic business journeys happen in a single day. 

“The thinking has been, ‘Supersonic flight would obviously be great, but nobody is doing it so therefore it must be impossible,’ ” the 44-year-old chief executive said during a recent interview. “Not true.”

Earlier efforts, including the Concorde, failed because of ill-conceived business models or other organizational problems as big aerospace companies struggled to shift to making new kinds of products. The technology needed to achieve supersonic flight, he argued, has been available all along. 

A self-taught aviation buff, Scholl regularly tangles with critics on social media, vacillating between snark and professorial counterarguments in his rebuttals. “I wish I’d thought about that before starting the company,” he shot back on X to a poster who noted that the Concorde was too expensive to operate. 

Scholl’s dream is dividing the aviation industry into two camps: those who think Boom will fail, and those who believe he’s the outsider who can finally revive supersonic travel. Scholl aims to have the company’s first jet, called Overture, flying by 2029. Last year Boom completed construction on a factory in Greensboro, N.C., where it plans to build the jet. It’s begun manufacturing a prototype of the engine that will power Overture. 

 

 

His fans include prominent startup investors, social-media throngs and Elon Musk and President Trump, who posed earlier this year with a model of the Overture jet. United, American and Japan Airlines have made preliminary orders for future planes. He’s backed by famed Silicon Valley accelerator Y Combinator, former United CEO Oscar Munoz, OpenAI founder Sam Altman. Former Boeing CEO Phil Condit sits on Boom’s board.

But Boom has recently scrambled to raise money. Its valuation, once close to $1 billion, was around $500 million at the end of last year, and the company has slashed its fundraising goals. Last fall it laid off roughly half its 260 employees. Boom has yet to begin building a full-size jet. 

Delta CEO Ed Bastian is among Boom’s doubters, calling the jet “a very, very expensive asset” for the roughly 75 travelers it is expected to carry—a fraction of a typical wide-body jet. He said he remembers the Concorde as a cool experience, but one he partook in only through free upgrades, never with his own money. He has no plans to buy Overture jets. “I wish them well,” he said.

Scholl is unfazed. He blames the lack of supersonic travel on an aerospace industry dominated by a pair of entrenched players, Boeing and Airbus, unwilling to shake up long-held business models. 

The company earlier this year flight-tested a smaller prototype and is working to ready a full-size production model for flight tests by 2027. 

At the test flight in January, Scholl stood by the control tower of the Mojave Air and Space Port north of Los Angeles in a crowd of around 200 people, including employees, investors and customers, as the sleek white XB-1 demonstrator took off. Then the group watched a livestream of the flight on a giant outdoor monitor as the single-seat plane zipped over the Southern California desert. 

The speed reading ticked up bit by bit before hitting Mach 1, or around 750 miles an hour, the speed required to break the sound barrier.

At the controls was Boom’s chief test pilot, Tristan Brandenburg, a graduate of the U.S. Naval Test Pilot School who also helped train participants in the Navy’s elite fighter-tactics program, known as Top Gun. 

“I’m not sure my brain’s fully caught up with me yet,” Brandenburg said after the flight. “I think it might still be flying supersonic.”

As for the window-rattling sonic boom that occurs when a plane travels faster than the speed of sound—and served as a cheeky inspiration for the name of Scholl’s startup—the CEO said the company has figured that out. 

Boom plans to quiet the sonic boom using a technique called Mach cutoff, though the approach has limitations and not all experts are convinced it’s possible to dampen the sound enough to keep it from being a nuisance. What’s more, the company’s business model doesn’t rely on flights over inhabited land, since it expects its planes to initially shuttle between New York and London or Paris.

President Trump signed an executive order on Friday directing the Federal Aviation Administration to repeal a five-decade-old ban on supersonic flight over land in the U.S.

Where a round-trip ticket on the Concorde cost upward of $10,000 in the 1990s, Boom says it will bring down the per-seat cost on Overture to that of a regular business cabin, which runs about $1,700 one way between New York City and London, though it will be up to airlines to set fares. He said Boom’s interiors will have business-class amenities and space, where Concorde was known more for being fast—and cool—than for being a comfortable ride. 

The concept behind the Concorde was buzzy in the 1960s, when the plane was designed and built under a French-British treaty. But supersonic flight’s heavy fuel usage became a liability by the time the plane made its debut in the 1970s, after an oil shock jolted jet-fuel prices higher and environmental worries were on the rise.

Airlines backed out of orders. British Airways and Air France were the only takers, and were heavily subsidized by their governments. Only 14 of the needle-nosed planes were built for commercial use.

By the end, Concorde was expensive to operate and maintain. Its glitz faded in comparison to more luxe amenities in regular-speed first-class cabins. Declining demand after a fatal crash in 2000 and the travel slump after the 9/11 attacks led to the jet’s retirement.

The Concorde’s fall from grace long fascinated Scholl. A lifelong aviation enthusiast, he spent years poring over textbooks on the science and engineering behind flight and, in his 20s, earned his private pilot’s license. 

“We’re not working with new technology here,” he said.

Boom can succeed financially, he says, by offering only business-class seats. Boeing’s effort to develop a supersonic plane failed in the early 1970s, he said, because the company was trying to create a jet that could fly passengers at all price points. 

Other companies have tried to develop supersonic business jets and small passenger planes since the Concorde was retired in 2003. Boeing took another try by backing a startup called Aerion that closed in 2021 after running out of money. The ventures stalled due to high costs, technical challenges and lack of demand, as speed simply hasn’t been a top priority for airlines. 

Other players are working on superfast flight, for both military and commercial applications. Lockheed Martin has paired with the National Aeronautics and Space Administration to develop a supersonic jet that flies without creating a deafening sonic boom. Atlanta-based startup Hermeus, which is working on a jet that would fly at hypersonic speed, five times the speed of sound, said this month that it successfully tested an unmanned prototype. Meanwhile, China’s state-owned Comac has said it aims to build a quiet supersonic jet.

Until Scholl started Boom in 2014, he jumped between startups for years after leaving Amazon in 2006, eventually landing a job as a midlevel executive at Groupon after selling his latest venture, an online-shopping software provider called Kima Labs, to the discount-coupon provider in 2012. 

“There is nothing like working on internet coupons to make you yearn to build something you truly love,” he wrote on LinkedIn. 

Scholl started floating his theory—that supersonic technology is well within reach but the business model just needed work—to investors, airline executives and Condit, the former Boeing chief who was at the jet maker when it killed its supersonic-plane program in the early 1970s after the U.S. government, daunted by high costs and technological hurdles, cut off funding for the project. 

Scholl founded Boom from his basement when he was living in the San Francisco Bay Area. He moved to Denver a year later and soon set up Boom’s first hangar at tiny Centennial Airport. A crew of employees plucked from other aerospace startups and small aviation companies began to tinker.

Boom designed its plane using carbon-fiber composite materials not in wide use when the Concorde was developed. Engineers used digital simulations rather than a physical wind tunnel to create the plane’s aerodynamic design. Boom’s Overture has a needle-nosed design similar to the Concorde’s. It relies on external cameras to ensure the pilots’ view. 

“I think of this as a company that’s not just building a cheaper supersonic plane,” Condit said. “But rather bringing a modern, Silicon Valley approach to disrupting aerospace in the way Tesladid in the automotive industry.”

Condit grew most concerned about Boom’s future in 2022, after Rolls-Royce, which was supposed to provide Overture’s engines, said it was backing out of the deal because supersonic flight was no longer a priority.

Scholl had a contingency ready by the time the breakup was official: Boom would piece together its own engine from the ground up, making some parts in-house and sourcing others from various suppliers. 

With the design set and an engine plan in place, Boom is now working to lock down the parts and factory tooling.

Some airlines have put in orders, but their deposits are relatively small. Japan Airlines invested $10 million in the company in 2017. United and American made smaller down payments, according to people familiar with the deals.  More funds from customers won’t flow until the planes are closer to being delivered, and the agreements were carefully crafted so airlines still have the option not to take them, the people said. 

After initially saying Boom needed to raise $6 billion to $8 billion to get Overture into production, Scholl now aims to raise $1 billion to $2 billion, which he says is enough to get the project to the stage where customer payments begin funding operations. Boom has raised $600 million so far. 

Munoz, the former United CEO and Boom investor, said he was impressed with how the company was able to streamline and stay focused when it ran into fundraising challenges last year, which he described as typical startup growing pains. He has helped make introductions to new potential backers.

“The funding thing was the scary thing that happened,” Munoz said. “The product itself, not scary.” 

Scholl shrugs off the challenges. 

“There’s this belief in the industry that to do these kinds of things requires billions of dollars, requires an army of people,” he said, referring to the recent layoffs. “And I sort of made the mistake of wanting to play into that.”

“He has kind of an iron will and he believes so much in the mission that he never doubts that he will find a way through,” said Jared Friedman, a partner at Y Combinator, the Silicon Valley accelerator that’s among Boom’s investors. “He started from basically no professional network in the space and a year or two later he’d come up with a thoughtful plan.”

Write to Sharon Terlep at sharon.terlep@wsj.com and Alison Sider at alison.sider@wsj.com