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.