Boom Supersonic and Rolls-Royce are no longer working together.
Boom Supersonic said it will drop the British manufacturer from its supplier roster and will seek out a new solution for engine development for its Overture supersonic jets in development.
"We are appreciative of Rolls-Royce's work over the last few years, but it became clear that Rolls' proposed engine design and legacy business model is not the best option for Overture's future airline operators or passengers," Boom told Space.com in a company statement.
Boom added that it's on the hunt for another supplier to help propel its jets faster than the speed of sound. "Later this year, we will announce our selected engine partner and our transformational approach for reliable, cost-effective and sustainable supersonic flight," the company said.
Who severed the relationship, which dates to 2020, is not clear. A media report suggested that Rolls-Royce might have initiated the separation.
"We've completed our contract with Boom and delivered various engineering studies for their Overture supersonic program," Rolls-Royce said in a statement to AIN Online earlier this week.
"After careful consideration," the statement continued, "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."
AIN suggested that fuel usage on the early-stage supersonic fleet might have concerned Rolls-Royce. The outlet also cited a customer (American Airlines, which ordered 20 supersonic jets last month) saying that there's time to work out the details, given that the first passengers wouldn't be on board until at least 2029.
"As Boom continues to develop the Overture aircraft, we will work together to better understand where, when and how it may best fit within our network and operation," an American spokesperson told AIN, adding that aircraft purchases are still subject to a finalized agreement.
Boom has signed multiple contracts at this early stage, including another deal with United Airlines in 2021 to eventually fly passengers at supersonic speeds. Boom has said it aims to fly passengers from Paris to Montreal in only 3 hours and 45 minutes, about half the current standard of 7 hours and 15 minutes.
The Overture aircraft Boom is working on includes a tapered fuselage, featuring a larger diameter in the front of the aircraft than the rear. (Boom says this unique design will reduce drag and increase fuel efficiency, allowing Overture to go as fast as Mach 1.7 over water and Mach 1, which is the speed of sound, over land.)
Other supersonic development work is being done by NASA, which is getting an experimental X-59 quiet supersonic transport ready for test flights, and Virgin Galactic, which is working on a Mach 3 aircraft for passenger travel.