Colorado-based aircraft startup Boom Supersonic has revealed the new propulsion system designed for its Overture supersonic airliner after Rolls-Royce announced its withdrawal from the project in September. Boom will be teaming with three industry leaders to develop the system called Symphony including Kratos Defense & Security Solutions, Inc.’s Florida Turbine Technologies (FTT) for engine design, GE Additive for additive technology design consulting, and StandardAero for maintenance.

“Developing a supersonic engine specifically for Overture offers by far the best value proposition for our customers,” said Blake Scholl, Founder and CEO of Boom Supersonic. “Through the Symphony program, we can provide our customers with an economically and environmentally sustainable supersonic airplane—a combination unattainable with the current constraints of derivative engines and industry norms.”

The Overture is being designed to carry 65 to 80 passengers at Mach 1.7 over water—or twice the speed of today’s fastest commercial aircraft—with a range of 4250 nautical miles. Optimized for speed, safety, and sustainability, Overture is also being designed to fly more than 600 routes around the world in as little as half the time. Flying from Miami to London in just under 5 h and Los Angeles to Honolulu in 3 h are among the many possibilities.

In July, Boom revealed the final production design of Overture, which Futurride covered here.

 

Custom propulsion design

The custom design of the propulsion system leverages proven technologies and materials to achieve optimal supersonic performance and efficiency, operating at “net zero carbon” and meeting ICAO Chapter 14 noise levels. When compared to derivative approaches, Symphony is expected to deliver a 25% increase in time on wing and significantly lower engine maintenance costs, reducing overall airplane operating costs for airline customers by 10%.

“United and Boom share a passion for making the world dramatically more accessible through sustainable supersonic travel,” said Mike Leskinen, President, of United Airlines Ventures. “The team at Boom understands what we need to create a compelling experience for our passengers, and we are looking forward to a United supersonic fleet powered by Symphony.”

Technical development partners are key to the Symphony project’s success.

FTT has leading supersonic engine design expertise including key engineers among the team responsible for the design of the F-119 and F-135 supersonic engines that power the Lockheed Martin F-22 and F-35 military aircraft.

“The team at FTT has a decades-long history of developing innovative, high-performance propulsion solutions,” said Stacey Rock, President of Florida Turbine Technologies. “We are proud to team with Boom and its Symphony partners and look forward to developing the first bespoke engine for sustainable, economical supersonic flight.”

The Symphony program will benefit from GE Additive’s track record of designing additively manufactured engine components—enabling more streamlined development, reduced weight, and improved fuel efficiency.

“GE Additive will bring industry-leading capabilities to Symphony, providing additive manufacturing design consulting and technology, while looking for additional areas to potentially collaborate,” said Chris Schuppe, General Manager of Engineering and Technology at GE Additive.

StandardAero, one of the aerospace industry’s largest independent maintenance, repair, and overhaul (MRO) providers, will ensure that the Symphony is designed for maintainability. Boom expects the collaboration to deliver maintenance services for the life of the aircraft and to benefit from StandardAero’s experience with supersonic engines.

“Our current qualifications, capabilities, and experience assembling and servicing supersonic military jet engines make us the intelligent solution for future commercial, supersonic engine MRO applications,” said Russell Ford, Chairman and CEO of StandardAero.

Symphony will be a medium-bypass turbofan engine with the same basic engine architecture that currently powers all modern commercial aircraft. Unlike subsonic turbofans, the new propulsion system will include a Boom-designed axisymmetric supersonic intake, a variable-geometry low-noise exhaust nozzle, and a passively cooled high-pressure turbine.

Engine design plans include a twin-spool architecture with no afterburner, a single-stage fan designed for quiet operation, and a passively cooled high-pressure turbine. Additive manufacturing will help with low weight, low part count, and reduced assembly costs. The final goal is 35,000-lb thrust at takeoff, optimized for 100% SAF (sustainable aviation fuel), and compliance with FAA and EASA Part 33 requirements.

 

Supporting Overture’s rollout

Symphony design is already underway to keep the supersonic aircraft on track to achieve type certification and carry its first passengers in 2029. Production is set to commence in 2024 at the Overture Superfactory in Greensboro, NC, with a rollout in 2026 and the first flight in 2027.

In September, Boom announced that it had selected Advanced Integration Technology (AIT) as the tooling and automation provider and integrator for the Overture final assembly line. Site preparation at the Superfactory is underway.

“AIT is proud to use our industry leading expertise in aerospace production system integration to support Boom’s vision of supersonic travel,” said Michael Wellham, AIT President and Chief Operating Officer.

Boom’s agreement with AIT spans the design, fabrication, and installation of custom tooling for the Superfactory and an end-to-end system for creating transportation and positioning tools for fuselage assembly, wing assembly, wing-to-fuselage joining, and final assembly. Major hardware provided by AIT will include automated drilling machinery, mobile transport equipment, and setups for positioning and joining setups. Boom is prioritizing the design and procurement of long-lead-time sections of the tooling suite, helping to ensure that the Overture program remains on track.

“This order will help ensure that the Superfactory is ready for Overture’s manufacturing launch in 2024,” said Chris Taylor, Vice President of Manufacturing at Boom.

As the company announced in January, it will hire more than 2400 workers at the Superfactory over the next ten years, and recruiting is underway. Boom also pledged to create over 200 internships for students in North Carolina universities, community colleges, and trade schools—and the first class of these interns is expected in 2023.

Also in September, Boom announced an agreement with Air Company to purchase up to 5 million gal of sustainable aviation fuel per year through the duration of Overture flight testing in Greensboro.

Boom also recently announced three Tier One suppliers that will contribute to key systems on Overture including Collins Aerospace, Eaton, and Safran Landing Systems.

 

American Airlines gets in line

United Airlines, in June 2021, became the first U.S. airline to sign a commercial agreement with Boom to add its aircraft to its global fleet as part of a cooperative sustainability initiative.

In August of this year, American Airlines, the world’s largest airline, placed deposits on 20 Overture aircraft and pre-ordered an additional 40, bringing Overture’s order book to $26 billion including orders and options. Overture would introduce an important new speed advantage to American’s fleet, which is currently the simplest, youngest, and most efficient among U.S. network carriers.

“Looking to the future, supersonic travel will be an important part of our ability to deliver for our customers,” said Derek Kerr, American’s Chief Financial Officer. “We are excited about how Boom will shape the future of travel both for our company and our customers.”

However, Boom must meet industry-standard operating, performance, and safety requirements as well as American’s other customary conditions before delivery of any Overtures.

“We are proud to share our vision of a more connected and sustainable world with American Airlines,” concluded Scholl. “We believe Overture can help American deepen its competitive advantage on network, loyalty, and overall airline preference through the paradigm-changing benefits of cutting travel times in half.”