Back in the late 1960s, British and French airlines formed an alliance to build a new, supersonic passenger jet. It would cruise above Mach 2 and fly from New York to London in 3.5 hours, compared with eight hours for conventional aircraft. Rising fuel prices, incredibly high operation costs, and limited routes all combined to make the Concorde difficult to operate, and the aircraft eventually retired in 2003. For the past 13 years, we’ve had no supersonic jets in-service with any airline — but Boom Technologies is hoping to change that. The company has been working on a new supersonic prototype design that would dramatically cut operating costs and improve efficiency, while reducing the sonic boom noise that got supersonic craft banned from overland flights decades ago. If their plan works, we could see a new wave of high-speed jets as early as 2020.
The XB-1 Supersonic Demonstrator (nicknamed the “Baby Boom”) is a one-third scale model of the final aircraft. The two variants are shown below — the first is the prototype, while the lower, larger aircraft is the planned full-size model, with room for up to 45 passengers (the Concorde could carry between 92 – 128 passengers). The XB-1 is said to be capable of cruising 10% faster than the Concorde, at Mach 2.2, and could reach London in a bit over three hours, or fly from Los Angeles to Sydney in 6 hours, 45 minutes as opposed to the 15+ hours it currently takes.
Vox has published an explainer delving into the history of the Concorde and how we might improve on supersonic designs compared with that aircraft. Computer modeling, material advances, and vastly more efficient jet engines will all have a significant impact on the vehicle’s operating costs and fuel consumption, while improvements to the aircraft’s design can be used to minimize the sound of sonic booms. The FAA banned the original Concorde from making overland flights because the sonic booms it created could be in excess of 135 decibels — as loud as a jet engine taking off from 100 feet away. NASA is working on designs that could cut the sound level down to 70 – 79 decibels, and while that’s still loud, it’s equivalent to a car passing nearby, not a jet engine running at full blast. For now, Boom Technologies is only planning over-water demonstrations, but if NASA can solve the sonic boom problem with its own ongoing X-plane research, it would give the supersonic industry far more available routes.
We don’t know much about the XB-1’s proposed fuel efficiency or specific design, but Blake Scholl, Boom’s founder, believes he can cut fuel consumption by 30% compared with the Concorde. The XB-1’s smaller size also means it could theoretically be less sensitive to demand drops. One of the reasons the Concorde wasn’t always profitable is because its operators had difficulty filling seats on the aircraft. The Concorde also burned an average of 8x more fuel per passenger mile than its competition of the day.
This efficiency gap could be the hardest issue to solve and may ultimately limit the XB-1’s usefulness. Improving the Concorde’s fuel efficiency by 30% would be an impressive gain, but it would still make the plane far more expensive than its modern competitors. With just 44 passengers on-board, the aircraft’s ticket price would be extremely sensitive to fuel prices. If Boeing has to pay 5% more for fuel, it can spread that cost over the 200-400 passengers on any given long-haul commercial flight. At $5,000 a seat, the XB-1 is already far more expensive than a conventional trip. While the difference is undoubtedly worth it for certain people, whether there’s enough of them to justify a major building effort is another question.