United Airlines announces deal with Boom Supersonic for faster-than-sound commercial flights

United Airlines said on Thursday that it had signed a deal with Boom Supersonic, a startup working to develop the first supersonic commercial jet since the Concorde, to purchase up to 50 of the company's planned passenger jet.

Under the deal, United would purchase 15 of Boom's Overture jet, which the startup plans to enter into commercial service in 2029, with the option for up to 35 more.

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The Concorde was retired in 2003 after it proved to be economically unsustainable for airlines, in a market that had for decades been focused on lowering costs and improving operating efficiency, rather than speed.

Boom, however, has insisted that it can make supersonic flight practical for the current airline market and more affordable for passengers.

Boom and United said on Thursday that United's future supersonic fleet would be considered net-zero carbon, and would fly entirely on sustainable aviation fuel (SAF).

"United continues on its trajectory to build a more innovative, sustainable airline and today’s advancements in technology are making it more viable for that to include supersonic planes," United CEO Scott Kirby said in a statement. "Our mission has always been about connecting people and now working with Boom, we’ll be able to do that on an even greater scale."

Boom, which introduced a conceptual single-seat tester aircraft in 2020, said it plans to introduce the prototype Overture aircraft, an 88-seat commercial airliner, in 2025, with the jet making its first flight the following year, before entering service in 2029.

While Boom CEO Blake Scholl has insisted that modern design tools and technology can help Boom overcome many of the challenges faced by the Concorde, the plane will still create a sonic boom when traveling at faster-than-sound speeds, limiting its use to over-ocean routes.

Still, the startup previously told this reporter during an interview that it had identified 500 different routes on which supersonic travel was viable, and said that its lower costs would translate to less-expensive fares, making the plane more viable than the Concorde was.

"The primary limitation on Concorde was economic. Because of the plane's fuel inefficiency, tickets were $20,000 a pop," Scholl said in October. "And you just can't fill 100 seats at $20,000. It made some money from here to London, but you can't build a business around that."

Fares are expected to be similar to today's business-class fares, Scholl said at the time, although the limited number of seats on the plane, combined with the high relative cost of SAF, make that optimistic.

Of course, airlines could also choose to charge more if the market exists, and may in fact need to — reducing weight will be a key to achieving efficiency, meaning it's unlikely that supersonic planes would earn additional revenue from carrying cargo, like many commercial flights today.

While United's agreement with Boom lends considerable legitimacy to the startup's plans, it's ultimately a low-risk investment for the airline.

"This is an order, but to call it a firm order is inaccurate," Mike Leskinen, United's head of corporate development, told The Air Current. "They have to deliver. And we've got a number of years to deliver on that," he added, citing financial protections built into the agreement.

Despite plans for the aircraft to be carbon net-zero, critics have cited the potential environmental impact of supersonic flight development. A report from NASA earlier this year cited numerous environmental hazards of faster-than-sound commercial travel, although the paper did not examine specific designs such as Boom's.

Although United will be the launch customer for the Overture, if and when the plane is certified by the FAA, it is not the first airline to link with the startup. Japan Airlines invested $10 million in 2018. The company was awarded a contract with the U.S. Air Force in 2020 to develop an executive jet for government officials — potentially including an Air Force One.

Notably, numerous airlines placed orders for the Concorde in the 1970s, including American Airlines, TWA, Continental and United, before eventually canceling.