Auto makers don't seem to be willing to get involved in Boom's supersonic jet.

According to Insider, Boom has lost its jet engine partner for the Overture supersonic plane, and other big engine manufacturers aren’t interested in the project either. Boom signed a “engagement agreement” with Rolls-Royce in 2020 for supersonic jet engines, but the latter revealed last week that it has withdrawn from the project. Other major jet engine manufacturers, including as Pratt & Whitney, GE Aviation, Honeywell, and Safran Aircraft Engines, have now notified FlightGlobal that they are not interested in supersonic aircraft at this time.

Airlines have placed an order for planes.

However, Boom stated that the project is still on track and that an engine partner would be announced shortly. “We can reaffirm our goal to unveil Boom’s chosen engine partner and transformative methodology for dependable, cost-effective, and sustainable supersonic flying later this year.” Insider was told by Boom. American Airlines has ordered 20 jets, and United has ordered 15. It intends to construct a plant in California and begin flying passengers by 2029.

Rolls-Royce, for its part, stated that “after careful deliberation… [we] have judged that the commercial aviation supersonic market is not currently a priority for us and will not continue further work on the initiative at this time.”

Following careful study, Rolls-Royce has concluded that the commercial aviation supersonic market is not a priority for us at this time and will not continue further development on the initiative.

There are just a few other manufacturers capable of producing a supersonic jet engine, and all of the major ones have stated that it is not in their plans. Honeywell, Safron, and GE all rejected the concept, and Pratt & Whitney argued that supersonic flight is “tangential” to their business.

Efficiency is a challenge for supersonic planes, according to Pratt & Whitney, and other manufacturers are concentrating on decreasing fuel use. Given the criticism of air travel’s impact to global warming, this is the industry’s principal focus right now. Furthermore, the International Civil Aviation Organization (ICAO) has slammed supersonic flight, claiming that it will consume 7-9 times more fuel per passenger, per kilometre, than subsonic planes.

It would compensate for its carbon burden

Boom has said that it would offset its carbon footprint by using sustainable aviation fuel (SAF). However, considering the increased fuel usage compared to a typical jet, the ICAO assessment stated that this would be a poor use of rare SAF fuels. It also said that “the high cruising altitude of supersonics greatly increases the residence duration of emissions.”