The list of potential engine providers to power Boom Supersonic’s Overture airliner project has narrowed following the decision by Rolls-Royce to withdraw from the Mach 1.7 project.
The U.K. engine maker had been partnered with Boom on propulsion studies for the supersonic airliner since mid-2020, but confirmation that these links have now ended comes as little surprise following recent comments by Chris Cholerton, president of civil aerospace for Rolls-Royce, who suggested there was little appetite to take the concept work forward into development.
Rolls-Royce’s withdrawal comes as the engine maker changes leadership and deals with the financial challenges from the COVID-19 market collapse, as well as recovering from the cost of fixing problems with the Trent 1000 on Boeing’s 787 fleet.
Despite the decision from Rolls-Royce, Denver-based Boom remains upbeat and says it will announce a propulsion partner within the next few months. The start-up aircraft maker also indicates the move to part ways with Rolls-Royce was a joint decision. “We are appreciative of Rolls-Royce’s work over the last few years but have mutually concluded their proposed engine design and legacy business model is not the best option for Overture’s future airline operators or passengers,” says the company in a statement.
Boom has offered few clues about the all-important engine selection, but company founder and CEO Blake Scholl has indicated the Mach 1.7 target cruise speed of the Overture, plus the recently revealed decision to develop a four-engine design, eases the technical challenges. This widens potential propulsion options around readily available cores.
The reliance on existing cores, in turn, could enable Boom to focus instead on developing a new type of business model for the day-to-day operation of the engine. Speaking earlier to Aviation Week, Scholl said “historically, those models have not been very customer friendly, and we want to do something that's not just a breakthrough in the engine technology, but something that is a breakthrough in the business model.”
Scholl added that “we are going to make an announcement this year. We have a pretty good idea of what it is and we are very excited about it.”
In a statement first reported by Aviation International News, Rolls-Royce says “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. It has been a pleasure to work with the Boom team and we wish them every success in the future.”
The official withdrawal of Rolls-Royce also makes General Electric and Pratt & Whitney the obvious lead contenders for the engine partner role, both having relatively recently developed civil supersonic concepts for the now defunct Aerion AS2 business jet based on the CFM56 and JT8D respectively. Development of the 16,000-20,000 lb. thrust CFM56-based engine, dubbed Affinity, was discontinued by GE following the collapse of Aerion in 2021.
However, with the precise thrust requirements of the Overture still undisclosed, it remains possible that derivative powerplants based on technology from cores of newer engines are in the frame. These range from the PW800/PW1000 family to GE’s GEnx-1 and Passport – the latter having recently flown just past Mach 1 during flight tests of Bombardier’s Global 8000 business jet.