Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

• Engine manufacturers are not interested in helping Boom build a supersonic powerplant, per FlightGlobal.
• The comments come after Rolls-Royce announced an end to its contract with Boom in early September.

Boom Supersonic may be forced to make its own engine for its ultra-fast Overture jet.

In 2020, engine manufacturer Rolls-Royce signed an "engagement agreement" with Boom to explore an engine that could power the faster-than-sound Overture, which already has orders from United and American Airlines.

However, Rolls-Royce told AIN Online in early September that it has since left the table.

"We've completed our contract with Boom and delivered various engineering studies for their Overture supersonic program," Rolls-Royce said.

"After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time," the company continued. "It has been a pleasure to work with the Boom team and we wish them every success in the future."

After Rolls-Royce's comments, GE Aviation, Honeywell, and Safran Aircraft Engines have all told FlightGlobal that they are not currently interested in making a supersonic engine for Boom.

GE previously worked on the Affinity engine that was being developed to power a supersonic jet from defunct planemaker Aerion, which was backed by Boeing before closing its doors in May 2021 due to financial challenges. But, the company revealed to FlightGlobal that "civil supersonic is not a segment that we are currently pursuing."

Pratt & Whitney, another company capable of making such an engine is also hesitant to participate, with chief sustainability officer Graham Webb calling supersonic jets "tangential."

Nevertheless, Boom is hard-set on finding an engine manufacturer and producing a power plant that is environmentally friendly. The company hopes its $200 million Overture jets will run on 100% sustainable aviation fuel (SAF).

"As a practice, we avoid commenting on any ongoing and confidential negotiation with our suppliers, until both sides are ready to announce jointly," Boom told Insider on Friday. "However, we can reconfirm our intention to announce Boom's selected engine partner and transformational approach for reliable, cost-effective, and sustainable supersonic flight, later this year."

With engine makers reluctant to partner with Boom, Henry Harteveldt, travel analyst and president of Atmosphere Research Group, told Insider that the company may need to make its own.

"Boom has stated it wants its aircraft to be as environmentally responsible as it can be, which is a noble and critically important objective, but it is already hard enough and expensive enough for Boom to build the airplane," he explained. "So, if they were to also take on the engine, then it will be a big challenge."

He emphasized that Boom will also have to make sure that its engine does not infringe on anyone else's patents or classified military designs.

"It doesn't mean Boom can't do this, but they will need to raise additional funds or bring in a partner or two to help," Harteveldt told Insider. "But, if it is successful in building the jet and the engine, then they get their aircraft and have very unique intellectual property and a business advantage because they will not rely on a third-party engine maker."

Moreover, if Boom is successful in building both, then it may become an "attractive acquisition target" for companies like Airbus or Boeing.

Or, in a case of irony, it could sell its powerplant design to an engine maker and "not only recoup its cost but also possibly make a profit off of it," according to Harteveldt.