__1931: __The world's first full-scale wind tunnel opens at Langley Field near Hampton, Virginia. With a test area 60 feet wide and 30 feet high, aerodynamic testing is performed on everything from World War II fighters and space capsules to submarines and modern jets.

Since the beginning of powered flight, wind tunnels have proven to be a critical part of the aerodynamic research needed to develop new aircraft. The Wright Brothers themselves built a small, 6-foot-long wind tunnel to test scale models of wing sections before their historic first flight in 1903.

But the limitations of using models were recognized early in aircraft design, and there was a desire to be able to test full-size structures and airplanes. Early in 1930 on a swampy corner of Langley Field in southern Virginia, construction began on a new wind tunnel that would allow engineers to examine actual airplanes in flight, without having to leave the ground.

In a massive building covering more than two acres, the wind tunnel used a pair of 35-foot propellers connected to 4,000-horsepower electric motors. Air was sucked through large funnel-like structures that directed a smooth flow of air past the staging area where airplanes, helicopters, race cars and even a Navy SEAL submarine were tested.

The wind tunnel allows engineers to examine real-world aerodynamics around objects, to confirm or test their calculations. Wind-tunnel discoveries are still made today that even the most advanced, modern computational fluid-dynamics software doesn't predict. In the era of slide rules and drafting tables, wind tunnels were even more valuable for discovering bugs in an aircraft design.

At an aviation conference in 1934, Orville Wright, Charles Lindbergh and Howard Hughes all watched as Boeing's latest fighter plane, the P-26 Peashooter, was tested at the Langley wind tunnel.

During World War II, every American fighter aircraft was tested in the facility. Word spread about its engineering capabilities, adding to the prowess of the American military. The Langley wind tunnel remained the world's largest until 1944.

The Langely wind tunnel was critical in drag reduction, allowing engineers and designers to clean up an airplane aerodynamically, allowing it to fly faster. And the drag reduction wasn't limited to airplanes. Modern semi trucks have been tested at Langley. It wasn't about getting more speed, but using less fuel.

As aircraft speeds increased after World War II, there was a need for wind tunnels that could provide faster-moving air. The 30-by-60-foot facility at Langley was limited to about 125 mph.

Eventually new wind tunnels were built that could test supersonic aircraft, providing wind speeds well over 1,500 mph. Others were built for even larger airplanes, including the world's largest wind tunnel at NASA's Ames Research Center south of San Francisco. That one can accommodate aircraft with 100-foot wingspans.

Operation of the Langley wind tunnel eventually passed from the military to NASA. It was added to the National Register of Historic Places in 1985 and was shut down in 1995.

However, a new agreement was reached for Old Dominion University to operate the facility, and the wind tunnel was used for several more years by many groups, including NASCAR teams.

Boeing tested one of its futuristic-airliner scale models, the X-48C, there. The airplane company was the last to use the first full-scale wind tunnel before it was shut down for good in September 2009, after 78 years of research.

But Langley is still home to nine other wind tunnels.

Source: Various

Top photo: A U.S. Navy Brewster XF2A-1 Buffalo sits on the test struts in the Langley wind tunnel in 1938. One of the tunnel's two giant propellers is visible in the background at left.

Courtesy NASA

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