On May 27, 1931, a massive new wind tunnel began operating at the Langley Memorial Aeronautical Laboratory (now the Langley Research Center) in Hampton, Virginia. Commissioned by the National Advisory Committee for Aeronautics (NACA), the appropriately named Full Scale Wind Tunnel was capable of testing full-size aircraft and held the record for the world's largest wind tunnel until 1944. The facility's open-throat, double-return test section measured 30 ft (9.1 m) high by 60 ft (18.3 m) wide, allowing it to accommodate aircraft with wingspans up to 40 ft (12.2 m). Two fans, each measuring 35.5 ft (10.8 m) in diameter and driven by a pair of 4,000-hp electric motors, circulated air in a closed loop at speeds ranging from 25 to 120 mph (40 to 193 km/h). The building that housed the Full Scale Tunnel was similarly oversized—at 434 ft long (132.3 m) and 222 feet wide (67.7 m), the footprint of the structure covered more than two acres.
The fan assembly preserved by the Museum is one of the last remaining objects from the Full Scale Tunnel. Together with its sister fan, it helped produce the wind used by the tunnel from 1938 to 2009. The complete assembly weighs 6,855 lbs (3,109.4 kg) and consists of four wooden fan blades and spacers, an aluminum nosecone, and a steel hub and hardware. For the first seven years of the tunnel's operation, all of its blades were made from cast-aluminum alloy, but facility leadership switched to wooden blades following the failure of a similarly constructed metal fan in another tunnel. By hand-carving each blade from laminations of soft Sitka spruce, Langley's in-house woodworking team could precisely shape and balance the fans. It was a testament to the quality of these craftsmen's work that the wooden blades were never replaced and only required minor maintenance in seven decades of operation.
The Full Scale Wind Tunnel proved to be an incredibly versatile piece of aeronautical research equipment. Through much of the 1930s, engineers used the tunnel to obtain data on fundamental research issues such as the aerodynamic effects of aircraft construction techniques and the use of flaps to optimize wing configurations. Early testing also helped determine the scale effects of various airfoil models and correlated results obtained in the tunnel with flight observations. As the country prepared for war, these generic research projects gave way to more practical efforts aimed at improving specific aircraft models for the U.S. military. From roughly 1938 to 1945, the Full Scale Tunnel became the go-to facility for aerodynamic drag reduction. Almost every aircraft in America's World War II arsenal—including such notables as the Grumman F4F Wildcat, the Douglas SBD Dauntless, the Republic P-47 Thunderbolt, the Lockheed P-38 Lightning, the North American P-51 Mustang, and the Vought F4U Corsair—found itself on the tunnel's test platform. Several of these famous aircraft models underwent extensive modifications following their time in the Full Scale Tunnel, signifying the value of the engineering work done there.
The Full Scale Tunnel continued to make significant research contributions in the decades after World War II. Ironically, the tunnel's relatively docile airspeeds were a major contributor to its longevity in the jet age since all aircraft operate at low speeds during take-off and landing. Early postwar testing focused on lift and stability issues encountered by supersonic aircraft, as well as the aerodynamic characteristics of hovering flight. Following the NACA's metamorphosis into the National Aeronautics and Space Administration (NASA), the Full Scale Tunnel provided critical support for a wide range of nationally important programs in the 1960s and 1970s, including Project Mercury, lifting bodies, V/STOL aircraft, supersonic transports, and Apollo astronaut training. Staff also developed expertise in the testing of dynamically scaled free-flight models and high-angle-of-attack technologies, capabilities that attracted renewed military attention and helped extend the tunnel's operational life through the mid-1990s.
Despite its prodigious research output, NASA decommissioned the aging Full Scale Tunnel in September 1995, arguing that newer facilities could better serve its core functions. From 1997 to 2009, the tunnel operated as a private business development venture under an agreement with Old Dominion University. The school managed dozens of projects during these years with test subjects ranging from racecars and Wright flyer replicas to communication towers and blended wing bodies. Following a final test run of Boeing's X-48 blended wing body on September 4, 2009, the Full Scale Tunnel went silent for good and was demolished on May 18, 2011.
