Boom recently lost its jet engine partner for the Overture supersonic jet, and other major engine manufacturers aren't interested in the project either, Insider has reported. After Boom signed an "engagement agreement" with Rolls-Royce for supersonic jet engines back in 2020, the latter announced last week that it had left the project. Now, other major jet engine manufacturers including Pratt & Whitney, GE Aviation, Honeywell and Safran Aircraft Engines have told FlightGlobal they're not currently interested in supersonic aircraft.
Boom said that the project is still on track, though, and that it will soon announce an engine partner. "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." Boom told Insider. The company has 20 airplanes on order from American Airlines and 15 from United. It plans to build build a factory in California and start flying passengers by 2029.
For its part, Rolls-Royce said that "after careful consideration... [we] have 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."
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.
There are a limited number of other manufacturers capable of developing a supersonic jet engine, and all of the biggest ones said that it's not in their plans. Honeywell, Safron and GE shut down the idea, while Pratt & Whitney stated that supersonic travel is "tangential" to its business.
Pratt & Whitney cited efficiency as an issue for supersonic jets, and other manufacturers said they're focused on reducing fuel-burn. That's the primary direction for the industry right now, given criticism of air travel's contribution to global warming. In addition, the International Civil Aviation Organization (ICAO) recently bashed supersonic travel, noting in a report that it would use 7-9 times more fuel per passenger, per kilometer, than subsonic jets.
Boom has said that it would offset its carbon output through the use of sustainable aviation fuel (SAF). However, the ICAO report said that would be a poor use of scarce SAF fuels, given the high fuel burn compared to a regular jet. It also noted that "the high cruise altitude of supersonics increases the residence time of emissions significantly."