Is the world’s first supersonic business jet a flight of fancy?

It was Barbara Amiel, whose copy I used to edit at the Sunday Times, who first alerted me to the important point that one private jet isn’t enough. One jet is always in the wrong place. Or having heavy maintenance. Two was the minimum, she said.

Plenty of others appear to live by the same maxim. Roman Abramovich has five jets, including a Boeing 787 Dreamliner worth $350 million. Elon Musk, Bill Gates, Jeff Bezos et al. are not short of a jet or two either.

But soon all these symbols of tycoonery may be made obsolete by the world’s first supersonic business jet, announced by a start-up unfortunately named Boom Supersonic (presumably after the noise its aircraft will make when it passes overhead).

Boom insists it has solved the sonic boom problem (which raises the question of why the company is in fact named Boom). But the aircraft will still be limited to subsonic speed over land, reaching Mach 1.7 only over water. Have we not seen this rodeo before?

The coming impact on the world of PJ ownership can only be imagined. Imagine the shame of disembarking from your Boeing Business Jet at Zug or Santa Monica to discover Mark Zuckerberg has just parked next to you in his new Boom Supersonic. Net zero? Pish tosh.

Boom Supersonic’s much hyped design for its aeroplane is not remarkable. Indeed it looks startlingly like Concorde (first flight 1969), with four engines slung below a delta wing, and a narrow fuselage. It seems ideally sized for billionaires hurrying to the climate change conference. Boom says it will fly in 2026.

Boom also claims that far from being a monstrous polluter and producer of carbon emissions, ‘it will be the first clean sheet airplane that was developed and optimised to run on 100 per cent sustainable aviation fuel’. This sounds promising except sustainable aviation fuel made from recycled biomass costs twice as much as kerosene, and claims that such fuels are entirely sustainable and benign are strongly contestable.

‘We are really focused on connecting people,’ says a company spokesman. ‘We ultimately want to be not only the fastest, but the most sustainable, and the most accessible aircraft for anyone to fly supersonic.’ All the buzz words are there. ‘Sustainable’, again. ‘Accessible’? Surely not. ‘Anyone’?

The United States Air Force has invested $60 million in Boom (not a lot in the grand scheme of things) and United Airlines has lent its name to the project, talking of a fleet of Boom Supersonics offering ultra-premium services. This all sounds exciting, but does it push Boom into the cone of reality?

I can think of a lot of problems beyond environmental activists gluing themselves to the forthcoming Boom. Thrust is a must, but Boom has yet to inform us of the engine that will power their supersonic. Engines can cost as much to develop as an airframe. Perhaps something will turn up.

Boom seems far-fetched, as mistimed as any aviation adventure could be when everyone else is scrambling to create zero-emission propulsion, using electric motors, going lower and slower. Even gigantic, well-established aircraft manufacturers face immense difficulties getting products to market. Boom is operating in a technically challenging environment which makes delay and cost inflation even more likely.

Finally, the evidence that media and financial engineering are well ahead of any actual flight, has, I admit, bothered me. Boom has a very pretty website. It’s very slick. But perhaps I underestimate the vast sums of money that seem to be available for some of the least plausible business plans. Virgin Galactic is years late launching its space tourism shuttle, although vast piles of investor cash have moved through the company.

Boom is a genius when it comes to self-promotion. Its Wikipedia page talks of its aircraft as a future Air Force One. Perhaps Boom’s supersonic jet will take to the skies. Perhaps Boom will find a way of making loads of them. Perhaps billionaires will buy them. Perhaps this isn’t a rerun of the 747 vs Concorde battle, when the tortoise crushed the hare. Perhaps airlines might find a profitable way of operating Boom Supersonics. Or perhaps not.