Supersonic Testing

Supersonic aircraft create a substantial sonic boom, meaning that they can't fly over populated areas without creating an intense noise disruption. NASA has been investigating ways to decrease this noise, which could revolutionize the way we fly.

Ray Castner, an aerospace engineer in the Inlet and Nozzle Branch at NASA's Glenn Research Center, has been testing nozzle concepts with the goal of dramatically reducing noise produced by supersonic aircraft. Castner and his team tested a small scale exhaust nozzle in the 1-by 1-Foot Supersonic Wind Tunnel at Glenn. Pressurized air was supplied to the nozzle, which was tested at simulated flight conditions of Mach 2. Early results are promising, and suggest that changes in pressure in the nozzle affect the sonic boom signature.

Friction Stir Weld

This close-up view of the friction stir weld tack tool used to manufacture of space shuttle external tanks shows the process of tack welding barrel panels together. Barrels were previously fabricated using traditional fusion welding, but friction stir welding is different in that the materials are not melted. A rotating tool pin uses friction and applied pressure to join the 20-foot longitudinal panels together.

Friction stir welding is the most recent upgrade to the space shuttle's external tank, the largest element of the shuttle and the only element that is not reusable. The new welding technique utilizes frictional heating combined with forging pressure to produce high-strength bonds virtually free of defects. Friction stir welding transforms the metals from a solid state into a "plastic-like" state, and then mechanically stirs the materials together under pressure to form a welded joint. Invented and patented by The Welding Institute, a British research and technology organization, the process is applicable to aerospace, shipbuilding, aircraft and automotive industries. One of the key benefits of this new technology is that it allows welds to be made on aluminum alloys that cannot be readily fusion arc welded, the traditional method of welding.

Smiles and Memories: A Final 'Goodbye' to the Langley Full-Scale Tunnel

It was a grand finale of sorts, a celebration that revisited the 78-year history of the Full-Scale Tunnel at NASA's Langley Research Center in Hampton, Va.

Engineers mingled with mayors. Alumni mingled with a new generation of NASA. Recollections mingled with respect.

"Many times it is referred to as 'the' Langley Wind Tunnel," said Joe Chambers, author and former tunnel branch head, who spoke to a standing room-only crowd at Langley's Reid Conference Center. In fact, it was only one of dozens of wind tunnels at NASA Langley.

A slideshow of the tunnel's history shown through photographs and quotes included music from the decades of the tunnel's operation. It set the ambiance for the ceremony that marked the official "goodbye." Demolition of the 30-by-60-foot tunnel is expected to begin early next year.

"We did 796 tests in this facility," said Chambers.

Chambers explained that the vision for a tunnel that would be 60 feet (18.3 m) across, 30 feet (9.1 m) high and with capabilities of speed surpassing 100 miles per hour (161 kph) started as a model in 1929. That model was under construction by 1930 and dedicated in 1931. It was built for $980,000.

As ideas arose, the tunnel evolved. In 1939, wooden blades replaced the original metal ones. "Those blades are the same blades that are in the tunnel today," Chambers said. Applause erupted.

During the years of the National Advisory Committee for Aeronautics, the tunnel attracted pioneers and luminaries like Orville Wright, Charles Lindbergh, Glenn Curtiss and Howard Hughes.

"When NASA was formed, the facility changed and began to develop space ideas," Chambers said. Modern times called for modern upgrades. Chambers noted the addition of a flight control computer.

And according to Chambers, the wind tunnel was producing more than just critical test results for improved flight -- it produced four NASA Center Directors. "There is no other wind tunnel or organization that provided four center directors to the agency," he said.

It also produced memories.

Gorden Helsel, mayor of Poquoson, Va., stared forward at the slideshow. "It's a landmark to this area," he said. "To a lot of folks out here, it's like losing an old friend."

He glanced over at the F-22 model. "I flew in one of those," Helsel said. "I spent 45 minutes in the air and was glad to get back on the ground." It was an experience made possible through testing at the full-scale tunnel.

Long Yip worked in the tunnel from 1977 to 1990. "I remember opening a textbook on aeronautics and the first thing I saw was the Full Scale Tunnel. I never imagined I would work there," he said.

Bob Huston began working at the tunnel in 1958. He recalled a time when one of his tests was interrupted by testing for Neil Armstrong and the lunar lander. "The test I was working on was delayed for six months," he said. In hindsight, Huston didn't mind so much.

Following the reception, many guests chose to revisit the tunnel located on the Langley Air Force Base side of NASA Langley. When attending alumni spoke up during a tour, the crowd circled and listened.

Clyde McLemore who worked there from 1947 to 1980, described a time when workers used slide rules, calculators and computers.

"When you say 'computers' -- you are talking about a person?" asked Dan Murri as he led guests throughout the tunnel.

"Yes, it was a girl we called a computer," McLemore responded with a smile.

The group continued on through the curvy turbulence vanes and across a walkway. It was the same walkway that Cameron Diaz walked on for a scene in the movie, "The Box," which is set to be released nationwide on Nov. 6.

At the next halt, McLemore looked up at a wooden propeller that stood about three stories tall. "The nose cone and tail cone were mine," he said.

"You designed those?" Murri asked.

"Yes," McLemore responded.

For many on the tour, the tunnel was being seen through the eyes of the alumni. And for the alumni, the tunnel was being seen through their younger selves.

Huston smiled at the tunnel's interior. He pointed to specific areas and recalled a funny story or a test that took place there. "Even when we worked extra hours during the war, it didn't matter much. It was still a fun place to work," he said.

The facility survived nearly eight decades. Its memory and history will survive much longer and so will its results. Tests conducted there include all of the World War II aircrafts, the P-51 aircraft, the Mercury entry capsule, submarines and NASCAR vehicles, to name a few.

Aviation Pioneer Richard T. Whitcomb

Aviation pioneer Richard Whitcomb has died in Newport News at the age of 89. The NASA Langley Research Center engineer has been called the most significant aerodynamic contributor of the second half of the 20^th century.

If you look at almost any large airplane today -- especially those that fly at supersonic speeds -- you can see the genius of Dick Whitcomb.

"Dick Whitcomb's intellectual fingerprints are on virtually every commercial aircraft flying today," said Tom Crouch, noted aviation historian at the Smithsonian Institution. "It's fair to say he was the most important aerodynamic contributor in the second half of the century of flight."

Born in Illinois in 1921, Richard Travis Whitcomb was the son and grandson of engineers. He grew up in Worcester, Mass., building model airplanes, in an era when aviation pioneers such as Charles Lindbergh were household names.

His interest in aeronautics continued into college at Worcester Polytechnic Institute, where he joined the aeronautics club and spent a lot of time in the school's wind tunnel.

Whitcomb came to what is now NASA's Langley Research Center in Hampton, Va., in 1943, during World War II, right after graduating with a Bachelor of Science in mechanical engineering and highest honors.

It was a busy time for aeronautical engineers working to improve America's military air superiority and Whitcomb dived right in. In less than a decade he tackled and solved one of the biggest challenges of the day -- how to achieve practical, efficient transonic and supersonic flight.

In interviews over the years Whitcomb told how he was sitting one day with his feet up on his desk when he had a "Eureka!" moment and came up with what is known as the Whitcomb area rule. He theorized the shape of the fuselage could be changed to reduce the aircraft shock wave drag that occurs near the speed of sound. The basic idea was to ensure a smooth cross sectional area distribution between the front and back of the plane. "We built airplane models with Coke bottle-shaped fuselages and lo and behold the drag of the wing just disappeared," said Whitcomb. "The wind tunnel showed it worked perfectly."

For that innovation the Langley engineer won the 1954 Collier Trophy for the year's greatest achievement in aviation in the U.S.

Whitcomb came up with three important aeronautical innovations while working at NASA Langley, one in each decade of his career. If the area rule was Whitcomb's major accomplishment of the 1950s, his supercritical wing revolutionized the design of jet liners after the 1960s. The key was the development of an airfoil that was flatter on the top and rounder on the bottom with a downward curve on the trailing edge. That shape delayed the onset of drag, increasing the fuel efficiency of aircraft flying close to the speed of sound.

In the 1970s it was an article on birds that led Whitcomb to develop his third significant innovation -- winglets -- refining an idea that had been around for decades. Other engineers had suspected that end plates added to the wing tips could reduce drag. But the Langley engineer proved a simple vertical plate wasn't enough. "It is a little wing. That's why I called them winglets," said Whitcomb. "It's designed with all the care that a wing was designed." Winglets reduce yet another type of drag and further improve aerodynamic efficiency. Many airliners and private jets sport wingtips that are angled up for better fuel performance.

Those who worked with Whitcomb remember him as brilliant, driven and single-minded with aerodynamics dominating his thoughts at work and at home. "I was extremely fortunate to work with Dick Whitcomb from 1974 to 1980, when I was an engineer fresh out of college," said Pete Jacobs, chief engineer for the Ground Facilities and Testing Directorate at NASA Langley. "It was truly an amazing experience to learn from the man who had been referenced in my textbooks. He had an uncanny sense of aerodynamics, unbelievable concentration, and the most phenomenal memory of anyone I've ever met."

The famed aerodynamicist retired from NASA Langley in 1980, but his contributions remain some of the research center's greatest accomplishments. "Dick Whitcomb's three biggest innovations have been judged to be some 30 percent of the most significant innovations produced by NASA Langley through its entire history," said Langley chief scientist Dennis Bushnell, who worked with Whitcomb. "That's from its founding in 1917 to the present. He is without the doubt the most distinguished alumnus of the Langley Research Center."

Whitcomb earned many honors in his life. Besides the Collier Trophy, he received the National Medal of Science (personally conferred by President Richard Nixon) in 1973, the U.S. Air Force Exceptional Service medal in 1955, the first NACA Distinguished Service Medal in 1956, the NASA Exceptional Scientific Achievement Medal in 1959 and the National Aeronautics Association's Wright Brothers Memorial Trophy in 1974. The engineer was also was inducted into the National Inventors' Hall of Fame in 2003, the National Academy of Engineering in 1976 for his pioneering research in the aerodynamic design of high performance aircraft and the Paul E. Garber First Flight Shrine at the Wright Brothers National Memorial. Whitcomb's alma mater, Worcester Polytechnic Institute, also awarded him an honorary doctorate and its presidential medal.

Whitcomb requested there be no funeral. Instead his ashes will be spread by plane over the Chesapeake Bay.