Print

Mail

wiki links

After 100 years, is there anything left to know about flight?

DPA, WASHINGTON
Wednesday, Dec 17, 2003, Page 9

Major advances have been made in flight in the 100 years since the Wright brothers first lifted off the soil of North Carolina, opening the doors for world travel while dramatically altering the way wars are fought.

But after 100 years of rapid progress, some wonder whether the boundaries of aerodynamics have already been reached, whether any major breakthroughs are awaiting discovery or if planes in the future will pretty much look and function as they do today.

"It's difficult to see where we go from here," said Richard Aboulafia, an aerospace analyst at Teal Group outside Washington. "The ideal jetliner, the ideal helicopter, the ideal fighter shapes have already been discovered, given what we know."

Since the historic flight at Kitty Hawk on Dec. 17, 1903, engineers have produced airplanes that have climbed to the edge of the atmosphere and broken the sound barrier, rockets that have propelled man to space and massive passenger jets like the Boeing 747 that have revolutionized world travel.

During the initial decades after the Wright brothers' first powered flight, rapid advances were made in the field, culminating with hi-tech fighter jets that can drop precision weapons and the 747, which can carry hundreds of passengers across vast oceans.

In the time between the 1920s and 1960s, key aerodynamic breakthroughs made those feats possible. Among them were the swept wing, which reduced drag and vastly improved the efficiency of airplanes by angling wings back from the fuselage. And there was the podded engine, a design for bolting a jet engine to the bottom of the wing -- like a pod -- rather than being built into it, an earlier design that caused wings to crack and sent scores of passengers to their deaths in the early days of commercial airline jet travel.

A key 1960s breakthrough, known as the "supercritical" airfoil, featured a more well-rounded leading edge on the wing and a flatter upper surface. The design allowed planes to travel close to the speed of sound while using fuel much more effectively. The advance was eventually incorporated into commercial planes, making it affordable to fly at high speeds over long routes.

Along the way, American Chuck Yeager surpassed the speed of sound, flying an X-1 in 1947, and the US government later developed the SR-71, the super spy plane that has flown faster and higher than any other.

But the boom in major breakthroughs in the science of aerodynamics had dwindled. Little since has changed.

"There is not much that is being discovered," said Ray Morgan, an aerodynamic engineer and retired vice president of AeroVironment, a firm near Los Angeles that develops prototype aircraft for the US space agency and Defense Department. "The revolutionary breakthroughs are now few and far between, and the learning curve is tapering off."

Morgan, now a consultant, said he believes aerodynamics is not a dead science but, instead, has matured into a field of incremental advances with a growing focus on complimentary technologies, like computers or lightweight construction materials, such as Kevlar, carbon fibre and other composites.

"Subtle changes to reduce drag or heating problems is not going to be the equivalent of the first time anybody flew faster than the speed of sound," Morgan said.

In recent years, scientists have returned to studying the source that first fed humankind's interest in flying: nature. For example, the Pentagon has poured millions of dollars into studying how birds, bees and other flying species propel themselves through the air, a concept known as "flapping-wing propulsion."

The Pentagon's Defence Advanced Research Projects Agency (DARPA) has been leading the effort, hoping concepts that exist in nature can be applied to the development of small aircraft for military purposes.

"We now have a pretty good understanding of how nature does it, and we are trying to see if we can create analogous mechanical systems," DARPA spokeswoman Jan Walker said. "You get a different aerodynamic flap, and we see from nature it tends to be the preferred solution and may be a better solution on a smaller scale."

"We are talking about small sizes, not something on the order of a 747," she said.

Morgan, who has worked at AeroVironment on the flapping-wing concept, said he believes it probably will not pay off for human flight but research into how birds and insects fly might offer some new and promising insight into aerodynamics.

"There might be something they're doing that people don't know," he said.

Other experts also doubted the notion that traditional aerodynamics has run its course.

A scientist at the US space agency's Langley Research Centre in Hampton, Virginia, which focuses on futuristic airplane designs, said there are other forces at play that will likely prod the aviation industry into forging new frontiers in aviation.

Dennis Bushnell, a senior engineer at the facility, said he believes the financial, environmental and air traffic control problems, coupled with a growing desire by companies to conduct business over the Internet rather than travel, will force the industry to develop a new strategy, and new technology along with it.

"The industry needs to simultaneously solve all of these problems, and there is no way to change in an evolutionary way the current aircraft to solve all of these problems," he said.

"Ongoing technology revolutions" in concepts like the blended wing design could capitalize on significant gains in efficiency, he said.

The blended wing design, which is likened to the flying wing, such as Northrop Grumman's B-2 bomber, could greatly reduce drag while allowing for a higher payload, meaning more passengers with more space for comfort on fewer flights.

"The only way to fix the problems is to reinvent the airplane," he said.
This story has been viewed 1974 times.