It would be a dream come true for the airline industry: A plane that uses up to 30 percent less gas to reach its destination, compared with today's jets. That's the promise of the blended-wing, a radically new kind of aircraft set to take to the skies for the first time this month.

His X-48B blended-wing prototype, now on the runway at Edwards Air Force Base, is only about a 10th the size of the 240-foot-wingspan craft he hopes to build. But the Pentagon is watching keenly. "Blended-wing technology can cost-effectively fill many roles required by the Air Force," says Capt. Scott Van-Hoogen of the Air Vehicles Directorate. As a tanker, for example, it could refuel two planes in midair at the same time.

For now Boeing is focused on making a military version of the plane by 2022. But by 2030 blended-wing aircraft could be carrying commercial passengers. Last November a team from MIT and Cambridge University unveiled the SAX-40, a blended-wing design that promises to be more fuel-efficient than a Toyota Prius - and thanks in part to the engine placement, just as quiet (at 63 decibels).