Boom Supersonic Says It Doesn’t Need The Usual Gang Of Subsonic Engine Makers

Let’s just say upfront that most people in aviation don’t think Boom Supersonic will succeed in producing a supersonic aircraft that regularly lures paying passengers on overwater flights. The doubters appear to include the world’s top aircraft engine makers, who over the past few months all backed away from the opportunity to power Boom’s planned Overture supersonic jet.

That did not deter Boom, which on Tuesday introduced a consortium of three lesser-known companies to design, consult on and maintain its engine, dubbed “Symphony.” Boom said Florida Turbine Technologies, a division of defense contractor Kratos Defense, will design Symphony; GE Additive will provide technology consulting on additive manufacturing and Arizona-based StandardAero will maintain it.

Denver-based Boom plans to produce Overture aircraft at a new plant at Greensboro, North Carolina’s Piedmont Triad International Airport, where Boom CEO Blake Scholl spoke Tuesday to about 150 employees, local officials, camera people and reporters. Groundbreaking for the plant, where employment is targeted to reach 1,750 workers, is expected in January.

Asked whether the engine makers left Boom or Boom left the engine makers, Scholl responded, “It became clear that this was far and away the best path for us to go. We could have taken a subsonic engine and adapted it. We could have taken a subsonic business model and adapted it.

“That works,” he said. “But it’s not nearly as good for our customers and our passengers because it brings the baggage of designs that were never optimized for supersonic flight and significantly increased operating costs.”

As for the timing of the switch, Scholl said, “We’ve had engine development underway since earlier this year in this approach.

“We’ve studied for several years what the propulsion system for the Overture needed to be able to do,” he said. “We did that alongside some of the best engine companies in the world. But in parallel we said ‘Let’s take a fresh look at what a fresh approach would be.’ The more we understood the subsonic world, the more we realized there would be significant benefit to be able to think differently.”

With subsonic engines, maintenance is costly and disruptive to operations, he said. In fact, typically, “the engines are given away,” he said. “All the money is for maintenance and parts.” Additionally, he said, subsonic engines work hardest at takeoff, while supersonic engines operate at full performance for hours. For them, “Takeoff is the easy part,” he said.

As usual, Scholl declined to comment on financing, except to say, “We’ve always assumed that Boom would be financing a significant portion of engine development. This way it’s more capital efficient, working directly with the supply chain.”

To review, Boom faced an engine challenge in November, when Rolls-Royce said it would end their partnership, announced in 2020, “to work together to identify a propulsion system that would complement Overture’s airframe.” On Tuesday, Scholl said he was grateful for the effort, noting “We first thought we could adapt a subsonic engine for a supersonic flight.” But the thinking changed.

Also in November, trade publication Flight Global reported that potential suppliers GE Aviation, Honeywell and Safran Aircraft Engines also showed no interest in developing engines for Overture. In December, I asked the president of Pratt & Whitney’s commercial engine division whether P&W would work with Boom. He brushed off the question, saying the company is busy making engines for narrowbody subsonic aircraft, including the Airbus A321. “We are 100% focused on existing programs,” he said. “We see the narrowbody market as a real opportunity.”

Tuesday was a big day for aviation in the Carolinas. As Scholl spoke in Greensboro, top executives of BoeingBA
and United Air Lines were in North Charleston, South Carolina to announce a large United order for Boeing 787s. No engine maker was announced, but the 787 is typically powered by either GE Aerospace’s GEnx or Rolls-Royce Trent 1000.

Asked his thoughts on the simultaneous events, Scholl said, “Supersonic flight is complimentary to subsonic flight.” He said Boom’s “ultimate goal is to enable supersonic flight for everyone who flies, [but] we’re starting with the focus on the premium passenger [and] being able to operate at fares 75% lower than (the norm) — Overture is just the start.”

At Piedmont Triad, North Carolina will pay $57 million to build a facility to house an assembly line, where supplies enter and finished products emerge. But Kevin Baker, airport executive director, said that the facility will be constructed with four garage door-type entrances on the side, so that it could easily be converted to maintenance bays. Baker said he is engaged with 13 companies who would like to locate on property adjoining the airport: about half of them would like to provide aircraft maintenance. “If Boom cannot use the facility, it can be converted to a different use,” he said.

The current schedule for Greensboro, Scholl said, envisions construction in 2023, production launch in 2024, rollout of the first Overture in 2026, flight tests in 2027, and Federal Aviation Administration certification in 2029.

Ambitious, sure, but the Wright Brothers were also ambitious. Scholl’s presentation was laced with references to the aviation pioneers who first flew in 1903 at Kitty Hawk, on the North Carolina coast about 300 miles east of Greensboro. The Wright Brothers jobbed out engine making to inventor Charles Taylor, Scholl said. “If we look back across history, great airplanes and great rockets have always been made possible by great engines,” he said, citing Space X and Blue Origin on the rocket side.

Speaking of Piedmont Triad’s selection as the production site, Scholl said, “There is deep passion for aviation in this state that goes all the way back to the Wright Brothers. We think it’s awesome that we’re building not too far from where the Wrights first flew.”

We are often told that hope is not a strategy. Tell the Wright Brothers.