(CNN) — When you absolutely, positively must eat breakfast in New York followed by lunch in London, there aren't currently that many options.

That could change in the not too distant future, as the first ever supersonic private jet takes a big step towards reality.

Dubbed "son of Concorde," the AS2 Supersonic Private Jet, a joint project involving aviation giant Airbus and Aerion Corp., has secured its first customer.

Business jet operator Flexjet has placed an order for 20 of the $120 million aircraft.

Designed to carry eight to 12 passengers at a top speed of Mach 1.5 -- that's 1,217 miles per hour or 1,960 km/h --its makers say it'll be able to carry up to 12 passengers from New York to London in four hours and 24 minutes.

Subsonic flights on that route currently take about seven hours.

If it gets clearance to fly cross-country, it also could link the Big Apple with Los Angeles in a couple of hours.

It's not due on the market any time soon, though.