Last month I reported that by 2029 start up Boom Technology, Inc. (Boom) planned to have an operational passenger airliner, the Overture, that would fly 65 – 88 passengers across the oceans at 1.7 times the speed of sound. The possibility of breaking the sound barrier on a civilian flight has been only a fantasy since the Concorde stopped flying. It now appears that supersonic flight for civilians will be just a pipe dream for longer than Boom had predicted.

Boom Overture supersonic airliner concept.

In the prior post, I noted that one of the major roadblocks to Boom’s plans was the fact that it had not identified an engine to power its supersonic airframe design. In 2020, Boom and engine maker Rolls Royce entered into a collaboration agreement pursuant to which Rolls Royce would explore the potential for developing the engines for Overture. Rolls Royce engines powered Concorde, the world’s first and so far only operational supersonic civilian airliner.

On September 8, Rolls Royce announced that it was terminating the collaboration agreement and giving up on the possibility of supplying engines for Overture. Last week, four other engine manufacturers GE Aviation, Honeywell, Pratt & Whitney and Safran Aircraft Engines all indicated they are not currently interested in making a supersonic engine for Boom.

Air France Concorde F-BVFF on static display at Paris CDG.

The disappointing news for Boom is also a setback for my home state of North Carolina. Later this year, Boom had been expected to break ground at the site of a proposed manufacturing and assembly plant in Greensboro, NC. It doesn’t make sense to start building a plant for a plane that has no engines.

This video succinctly summarizes Boom’s ambitious plans for supersonic civilian airliners.

Boom is not necessarily bust. Among other options, Boom can look for other engine manufacturers that are willing to take on the challenge of building a new engine capable of supersonic flight while meeting Boom’s goal of using 100% sustainable aviation fuel produce a zero net carbon emission. Or Boom could design and build the engines itself — if it can find investors willing to take the substantial risk.

The major roadblock with designing and building a new engine is having confidence that enough Overtures will be built to make the new engine profitable. Although Boom has received a handful of non-firm orders for Overture from several airlines including American Airlines, United Airlines and Japan Airlines, there doesn’t seem to be enough demand for high-cost supersonic travel to justify building planes in the numbers that would be required to turn a profit for the plane, the engines and the airlines. That is the same issue that led to the cancellation of Concorde.

In sum, the prospects for Boom and Overture are dimming but not yet totally extinguished. Purely from the view of an aviation enthusiast, civilian supersonic air travel sounds great. In spite of technological advances since Concorde, economic and environmental challenges remain difficult if not impossible to overcome. Overture sure looks nice on paper though.

Are you in favor of the development of supersonic airliners like Overture?