Overture’s Symphony supersonic engine at its Denver facility, and officially confirms the target thrust level for the new centerline turbofan has grown to 40,000 lb.
The company plans to assemble the prototype core for testing starting around year’s end at its recently acquired test site at Colorado Air and Space Port in Watkins. Located close to Denver International Airport and the company’s Centennial headquarters, the facility will be expanded for follow-on, full-up propulsion system tests later in 2026.
Boom founder and CEO Blake Scholl noted July 28 on social media that “first chips” had been cut by a computer numerically controlled lathe that was newly installed in the company’s Denver “Supercenter” facility. Other recently acquired machine tools include a 65,000-lb. mill for producing precision machined large castings and forgings. Parts will be combined with a growing collection of other core components already produced, including additively made turbine blades and outer blade air seals.
Texas-based high-temperature materials and components partner ATI is providing materials for Symphony’s high-pressure compressor integrated blade and disk stages, as well as the turbine disk. Other engine partners in the Boom-led propulsion program include Standard Aero and Florida Turbine Technologies (FTT), a unit of Kratos.
In development for Boom’s planned Mach 1.7 Overture airliner, the two-spool, 3:1 medium-bypass turbofan engine will feature a single-stage 72-in.-dia. hollow blade fan and be optimized for prolonged supersonic operation with an air-cooled, single-stage high-pressure turbine and three-stage low-pressure turbine. The overall propulsion system will weigh 14,000 lb. and measure 41-ft. long, of which 12 ft. will be made up by the core.
Originally targeted at around 35,000 lb.-thrust, Boom’s design analysis subsequently indicated the requirement for additional thrust. Although
hinted at by Scholl earlier this year, the move to 40,000 lb.-thrust was confirmed by David Lazzara, staff scientist in aerodynamics at Boom.
Speaking at the American Institute of Aeronautics and Astronautics Aviation Forum in Las Vegas on July 25, Lazzara says Symphony “is an ambitious attempt to bring a new engine to market that fits in between existing off-the-shelf options as a 40,000 lb.-thrust class medium bypass ratio engine. It is already designed to be 100% sustainable aviation fuel (SAF) compatible, so that we can plug that in once the infrastructure is ready for use.
“On top of that, it has a key set of design features going from the inlet to the trailing edge at the back of the nozzle that enables it to meet the noise regulations as part of the package overall with Overture,” Lazzara says. “We have some experienced partners in the industry that have helped with the turbomachinery design, as well as others who have been a part of engine OEMs and aircraft OEMs that have come together to bring the design in a way that would not be possible by simply pulling an off-the-shelf engine.”
Explaining the difference between a conventional aircraft design approach and the integrated airframe-engine process underway at Boom, Lazzara says “airframe design and the engine design are basically two separate design worlds that are brought together and oftentimes in a suboptimal marriage. When Boom made the choice to bring the engine in-house, they essentially brought those two worlds and made them one, allowing for optimal integration, mission performance and even closure of a business model. This is what sets Boom apart from other attempts at high-speed flight in the past,” he adds.