Can Supersonic Flights Really Succeed?

The supersonic Concorde jet made its last commercial passenger flight on Oct. 24, 2003. The Anglo-French plane was a wonder to watch, but could never overcome its high costs and concerns over its noise.

Is supersonic travel ready for its next act?

In June, United Airlines Holdings Inc. said it would buy 15 small supersonic jets being developed by Boom Technology Inc. Boom hopes to fly a scaled-down prototype of the so-called Overture jets later this year, with the full-size jet ready by the end of the decade.

Boom says the jets would be able to fly at Mach 1.7, or 1.7 times the speed of sound, enabling passengers to fly from London to Newark, N.J., in 3½ hours; it currently takes over six hours. A flight from San Francisco to Tokyo would take six hours, down from over 10 hours.

Proponents say this can happen, if entrepreneurial vision and market forces are allowed to work. Skeptics doubt that the demand will be there, given the likely cost of a ticket.