Why Airlines Need Competition .
Future of flight gets a lift with 'blended wing' design
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 nearly big enough to hold a human being or much else.
If all goes as planned, though, full-scale versions of Boeing Co.'s unusual 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. The X-48B is made not for secrecy or speed, however, but for heavy lifting and high efficiency.
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 to 30 percent. That could make planes based on the design 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 amount of money 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.
When it comes to improving the efficiency of airplanes, the military could use everything it can get. 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 improve gas mileage and limit dependence on foreign oil. But to really increase efficiency in the future, 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 Boeing's experimental airplane more efficient is aerodynamics. Instead of a typical tube with wings and tail attached, the X-48B design has no tail, and the fuselage blends in smoothly with the wings. The design substantially reduces drag and improves lift.
When it comes to fuel efficiency, "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."
Design isn't new
So-called "flying wing" designs like the X-48B aren't new.
As far back as 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 of Northrop's XB-35 and YB-35 planes to be used as 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. Shortly into the flight, the crew lost control, and the plane broke apart, killing everyone on board.
Despite their infamous past, the early flying wings ultimately influenced the design of Northrop Grumman Corp.'s B-2 stealth bomber. And last year, the Defense Department's research division selected Northrop Grumman to design what could become the first-ever supersonic flying wing. The company expects to start test flights of its "Oblique Flying Wing" by 2011.
It's at the former Muroc Field — renamed Edwards Air Force Base after Glen Edwards' flying wing disaster — where Boeing, NASA and the Air Force Research Lab are conducting the test flights of the X-48B.
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.
"It can have some really nasty flying characteristics," he said.
High-technology makes the difference
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 become reality within 15 years. After that, they could be adapted for commercial use.
Boeing is about to take a month-long respite from test flights to analyze the data it has collected so far, but plans to resume flights at Edwards and ultimately take the X-48B into the air 25 times by the end of the year.
"As far as first flights go, they've gone about as smooth as anybody could expect so far," Princen said. "We haven't had any surprises."
Of course, remotely flying an experimental, unmanned plane is one thing. Putting them into production and use is another thing altogether.
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 used to making tube-wing-and-tail designs 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.
Other experimental planes have come and gone over the years, many never making it even as far as the X-48B has so far.
Natalie Crawford, director of the Air Force program at consulting and research firm Rand Corp., said technical demonstrations like Boeing's are only the beginning of a long and arduous process. If the blended wing design is ever to become anything more than an experiment, Boeing must ultimately convince the Air Force that such planes are needed, then convince the government to spend billions to buy them — not easy tasks by any measure.
"This is a first step," Crawford said. "It's an important first step ... but it's just a first step."
--------------------------------------------------------
By: BOB KEEFE
The Atlanta Journal-Constitution
Source: http://www.ajc.com/
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 nearly big enough to hold a human being or much else.
If all goes as planned, though, full-scale versions of Boeing Co.'s unusual 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. The X-48B is made not for secrecy or speed, however, but for heavy lifting and high efficiency.
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 to 30 percent. That could make planes based on the design 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 amount of money 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.
When it comes to improving the efficiency of airplanes, the military could use everything it can get. 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 improve gas mileage and limit dependence on foreign oil. But to really increase efficiency in the future, 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 Boeing's experimental airplane more efficient is aerodynamics. Instead of a typical tube with wings and tail attached, the X-48B design has no tail, and the fuselage blends in smoothly with the wings. The design substantially reduces drag and improves lift.
When it comes to fuel efficiency, "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."
Design isn't new
So-called "flying wing" designs like the X-48B aren't new.
As far back as 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 of Northrop's XB-35 and YB-35 planes to be used as 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. Shortly into the flight, the crew lost control, and the plane broke apart, killing everyone on board.
Despite their infamous past, the early flying wings ultimately influenced the design of Northrop Grumman Corp.'s B-2 stealth bomber. And last year, the Defense Department's research division selected Northrop Grumman to design what could become the first-ever supersonic flying wing. The company expects to start test flights of its "Oblique Flying Wing" by 2011.
It's at the former Muroc Field — renamed Edwards Air Force Base after Glen Edwards' flying wing disaster — where Boeing, NASA and the Air Force Research Lab are conducting the test flights of the X-48B.
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.
"It can have some really nasty flying characteristics," he said.
High-technology makes the difference
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 become reality within 15 years. After that, they could be adapted for commercial use.
Boeing is about to take a month-long respite from test flights to analyze the data it has collected so far, but plans to resume flights at Edwards and ultimately take the X-48B into the air 25 times by the end of the year.
"As far as first flights go, they've gone about as smooth as anybody could expect so far," Princen said. "We haven't had any surprises."
Of course, remotely flying an experimental, unmanned plane is one thing. Putting them into production and use is another thing altogether.
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 used to making tube-wing-and-tail designs 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.
Other experimental planes have come and gone over the years, many never making it even as far as the X-48B has so far.
Natalie Crawford, director of the Air Force program at consulting and research firm Rand Corp., said technical demonstrations like Boeing's are only the beginning of a long and arduous process. If the blended wing design is ever to become anything more than an experiment, Boeing must ultimately convince the Air Force that such planes are needed, then convince the government to spend billions to buy them — not easy tasks by any measure.
"This is a first step," Crawford said. "It's an important first step ... but it's just a first step."
--------------------------------------------------------
By: BOB KEEFE
The Atlanta Journal-Constitution
Source: http://www.ajc.com/
0 komentar:
Post a Comment