Boom finds a new design partner for its Symphony supersonic jet engine

Overture test flights are set to start a year later than previously planned, though.


Boom has revealed more details about Symphony, the engine for the Overture jet with which it aims to bring back commercial supersonic air travel after the retirement of Concorde. Most importantly, the company has secured a new partner to develop the engine after it parted ways with Rolls-Royce in September.

FTT, a division of Kratos Defense & Security Solutions, will help design Symphony. Some of FTT's engineers were behind the F-22 and F-35 fighter jet engines, so they have experience in powering supersonic aircraft.

Symphony is a medium-bypass turbofan engine that will have the same basic architecture as current commercial aircraft engines. However, Boom says its new propulsion system is designed to help Symphony achieve 35,000 pounds of thrust and speeds of Mach 1.7. Boom claims that Overture will be able to fly between Newark and London in under four hours and San Francisco to Tokyo in around six hours.

Boom expects Symphony to deliver a 25 percent increase in time on wing (i.e. in-flight time) and claims it will have significantly lower maintenance costs than other engines. The engine will be the first that's optimized for fully sustainable aviation fuel, Boom says, and it will operate at net zero carbon. Symphony will also have a single-stage fan that's designed for quiet operation.

Despite the switch in engine partners, Boom says the jet is still on track for certification in 2029. Production is set to start in 2024 at a factory in North Carolina with the first jet scheduled to leave the factory in 2026. Boom now expects test flights to start in 2027, a year later than previously planned.

The company already has customers lined up. American Airlines placed an order earlier this year for 20 jets, with an option for another 40. United Airlines, meanwhile, has ordered 15 Overture planes with an option for another 35.