And as if this change in circumstance weren’t enough: a year after my article and book appeared, the company that had made the boldest promises about its ability to deliver a small, cheap jet—Eclipse Aviation, of Albuquerque, the very company I had featured in my story—revealed the humiliating news that the radically light and efficient new engine around which it had designed the airplane was just not going to work. Eclipse put plans for its vaunted new EA500 jet on hold until it could figure out a replacement engine.

Because of problems like these—and more—the aviation establishment has also been highly skeptical that light-jet air taxis could ever pay their way. The prominent analyst Richard Aboulafia, of the Teal Group, in suburban Washington, has argued that the potential market is so small, and the costs and risks so large, that the air-taxi concept is mainly hype and wishful thinking.

Certainly, the vision might turn out to be a mirage. Given the rocky history of most air-travel companies, that may be the most likely result. Still: early this year, on a visit home from China, I stepped inside one of those very same EA500 airplanes and took a 40-minute flight at more than 350 miles per hour. The plane took off from Boca Raton, Florida, which has a small airport but no commercial airline flights. It landed about 160 miles north in Florida at Lakeland, a sizable inland city with a large runway-and-terminal complex but no commercial flights. If I’d been driving, the trip would have taken about four hours. If I’d booked this seat on the plane (it was a free demo flight), I would have spent about $275—a tiny fraction of normal business-jet costs, and about $50 less than a US Airways shuttle between Washington and New York, which covers about the same distance.

Two pilots sat in the front of the airplane, whose interior is the size of an unusually roomy SUV’s. After the plane had climbed above 10,000 feet, one of them turned around and offered to chat and answer questions. I sat in the second row, in one of two leather bucket seats with as much legroom as domestic airlines offer in first class and plenty of room for working on a laptop or with an open briefcase. In the other seat was Bruce Holmes, a retired NASA official who had spent much of his career developing plans and promoting support for a “Small Aircraft Transportation System,” which he imagined as a modern aerial complement to the interstate highways. There was space for one more passenger, in a seat behind us that had less legroom but as much as normal airline economy class. The plane is designed for shortish business trips rather than long hauls with a lot of cargo, but it allows up to 40 pounds of baggage per passenger.

The flight was operated by the DayJet company, the most successful and fastest-growing of several companies that are racing to put Holmes’s vision into practice. Others include SATSAir and ImagineAir, which operate in the Southeast using propeller-driven Cirrus SR-22 airplanes, with four seats and a parachute that can bring the whole airplane down safely in an emergency. Linear Air, another new air-taxi company, serves cities in the Northeast with Cessna turboprops and Eclipse jets. At the beginning of last year, DayJet, which is based in Boca Raton, had 70 employees but no airplanes or paying customers. Last September, it carried its first paying customer on its first “on demand” flight (from Boca Raton to Tallahassee), meaning the customer—and not an airline schedule—specified when he wanted to leave and arrive. By the time I visited, this February, it was operating 28 Eclipse airplanes, serving 45 cities in Florida and the Southeast, and employing 270 people. By the end of this year, DayJet expects to be flying 100 airplanes, serving 100 destinations, and employing 800 people. Of the 350 customers who had used its service within the first three months, 40 percent had booked a repeat flight.