Los Angeles --- It has taken wing a half-dozen times now, like a white manta ray streaking over the dusty Mojave Desert northeast of here.
The experimental plane is just a scale model, controlled remotely from the ground. With its 21-foot wingspan, it's bigger than a kid's model, but not big enough to hold a human being or much else.
If all goes as planned, full-scale versions of Boeing Co.'s X-48B airplane may forever change the shape of aviation.
Called a "blended wing body," the three-engine plane vaguely resembles a B-2 stealth bomber. But the X-48B is made for efficient heavy lifting.
Researchers say the new design and the lightweight, plasticlike composite materials it's made from could improve the fuel efficiency of future planes by 20 percent to 30 percent. That could make these or similar planes ideal for hauling heavy cargo long distances and, perhaps ultimately, for carrying more passengers than today's typical commercial airliners.
As a result, the X-48B has attracted keen interest from NASA, the Air Force Research Laboratory and others. Officials from the Air Force lab, located at Wright-Patterson Air Force Base near Dayton, Ohio, have shelled out an undisclosed sum to help pay for the testing, and have helped shuttle the two experimental aircraft based on the design around the country for testing.
"My understanding is that it has the potential to be a very efficient plane," said Lt. Scott Vanhoogen, X-48B project manager for the Air Force Research Lab.
The Air Force alone uses about 3 billion gallons of fuel each year, or about 8 million gallons every day.
Already, it is considering a wide variety of options for existing planes --- everything from replacing old engines with more efficient ones to using synthetic fuels that blend petroleum with natural gas or other additives --- to make planes more fuel-efficient. But to really increase efficiency, observers say, the Air Force must consider new aircraft designs.
"To make double-digit improvements, you have to move beyond the current design standard," said Richard Aboulafia, vice president of analysis at Teal Group, a commercial and military aircraft consulting firm. Boeing's blended wing design, he added, "is one of the more promising designs out there."
The lighter-than-metal composite materials help, but what really makes the experimental plane more efficient is aerodynamics. Instead of a typical tube with wings and tail, the X-48B design has no tail, and the fuselage blends in smoothly with the wings, reducing drag and improving lift.
"It's a bit like a hybrid car" in its advantage over conventional designs, said Norm Princen, the chief engineer in Boeing's Phantom Works division who's responsible for the X-48B project. "That's what makes this very attractive, especially when such a large part of the Air Force's operating budget is fuel expenses."
So-called "flying wing" designs aren't new.
In the late 1920s, aviation pioneer Jack Northrop began experimenting with flying wings, and in the 1940s rolled out the first U.S. airplanes based on the design.
After World War II, the military ordered more than a dozen Northrop XB-35 and YB-35 planes for bombers.
But like other flying wings, the planes were plagued with problems. In June 1948, renowned Air Force test pilot Capt. Glen Edwards and a crew of four took off in a jet-powered version of Northrop's flying wing from what was then called Muroc Army Air Field in California (now Edwards Air Force Base, named after him). Shortly into the flight, the crew lost control, and the plane broke apart, killing all aboard.
Despite their infamous past, the early flying wings influenced the design of Northrop Grumman Corp.'s B-2 bomber. And last year, the Defense Department selected Northrop Grumman to design what could become the first supersonic flying wing. The company expects to start test flights by 2011.
Because it lacks a tail for stability, the new design isn't immune to the same sorts of control problems as the early flying wings, acknowledges chief engineer Princen.
What's different today, Princen added, is technology.
Special software and computers constantly adjust a long series of curved flaps along the edges of the wings, helping solve many of the pitch and yaw problems Edwards and other test pilots of the early flying wings encountered, Princen said.
Composite material construction techniques Boeing pioneered with the design of its much-vaunted forthcoming passenger plane, the 787 Dreamliner, help with pressurization problems and other issues.
Princen said full-scale working military planes based on the X-48B design could fly within 15 years. After that, they could be adapted for commercial use.
Aboulafia, the industry analyst, said there are clear reasons why earlier flying wing designs didn't make it into mass production.
To build them, manufacturers would have to completely change factories and retrain workers. Likewise, pilots and ground crew would have to be retrained to fly and maintain them.
"You'd have to change everything," Aboulafia said.
X-48B AT A GLANCE
* What: New type of fuel-efficient plane made from plasticlike composites and a "blended wing" design that eliminates a tail and standard fuselage. Two 400-pound prototypes come with three turbojet engines capable of pushing the planes at about 180 mph.
* Who: Boeing Co., NASA and the Air Force Research Lab at Wright-Patterson Air Force Base in Ohio are jointly conducting test flights of scaled-down prototypes.
* Where: Boeing, NASA and the Air Force are testing prototypes at Edwards Air Force Base in California.
* Why: The Air Force is considering the design for future cargo planes as it looks for ways to reduce fuel costs and dependency on foreign oil. If the design is successful, commercial airlines could someday consider it, too.
* When: Researchers say it will be at least 15 years before working military models are available. Commercial aircraft based on the design could come after that.
