One year ago, North Carolina Governor Roy Cooper announced the arrival of Boom Supersonic. The aerospace startup would locate its factory at Piedmont Triad International Airport, generate some 1,700 good-paying jobs, and bring hundreds of millions of dollars of investment to the region. Overture, the proposed zero-carbon, sustainable, affordable supersonic passenger jet would connect the world at record speeds with the least damage to the environment.
But test flight delays, lack of interest on the part of major engine manufacturers, and the announcement in December to design and develop the plane’s engine in-house have generated some skepticism. Dan Rutherford is program director for the International Council on Clean Transportation. He spoke with WFDD’s David Ford.
On sustainable aviation fuels:
Currently, about 1/20th of 1% of global fuel use is sustainable aviation fuels. And they carry a high-cost premium, generally somewhere between two and five times the cost of fossil jet fuel. So, you know, they're an emerging technology that people think are critical to decarbonizing the aviation sector we have today. There's a separate question of well, how suitable would they be for new supersonic aircraft. And we’ve looked into this with some research partners at the Massachusetts Institute of Technology. We released a study on this back in January. And basically, the study concludes that first of all, the economics of combining [a] supersonic jet with these fuels that have a high-cost premium don't look good. That is, you know, we know from the experience of Concorde, that supersonic operations tend to not be profitable sort of baseline, and then adding on a very expensive fuel looks like it will make it hard for the airlines to pencil out. Finding number two is a little bit counterintuitive. But if you take a sustainable aviation fuel, and you burn it in a supersonic aircraft that operates at a very high altitude, typically somewhere between 50,000 and 55,000 feet, you can actually have climate disbenefits. That is, you can actually increase rather than reduce the climate impacts just because of the compositions of the fuels themselves.
On airport noise and supersonic booms:
So, the airport noise question I think is largely addressable. Boom believes it can manufacture an aircraft that can meet — we call them either chapter 14, or stage five noise standards. The sonic boom is a much trickier one, because currently, this boom is so disruptive, that supersonic airliners are only allowed to operate over water. And that severely limits the number of routes that they can be used on. Concord was tried out on a variety of routes worldwide. But because of the overland flight ban, ultimately, it was only used on two routes regularly between London Heathrow and JFK and Charles de Gaulle and JFK. And that prohibition continues to this day.
On what Boom Supersonic may know that we don't:
It actually goes broader than that. It's what doesn't Boeing, Airbus, GE, Pratt & Whitney, Rolls-Royce, what do they not know? Because those companies also don't see a business case for supersonic aircraft. So, I don't know. It's really a question for the company. I mean, they're clearly believers in the technology and the potential market, but they are trying to do something very difficult that other companies have decided is probably not commercially viable. There is a history on Aerion where — so, Aerion in essence was a company similar to Boom that couldn’t get strong support from the legacy engine manufacturers and therefore was paying GE to develop an engine for it. And ultimately it was that sort of ongoing development cost that drove Aerion out of business. Both Boeing and Airbus were investors at one point, and they supported the project. They looked at the books and ultimately concluded that it wasn't for them. And we've seen a similar outcome from the contract that Boom had with Rolls-Royce. So, that is kind of the key question is like what is Boom seeing that the incumbent manufacturers are not?