In 1929, the National Advisory Committee for Aeronautics, an organization that would become NASA Langley Research Center, began construction on a massive and unique facility: the Full-Scale Tunnel. Housed in a huge building in Virginia, the nation's first wind tunnel for testing full-size airplanes had a 30-foot by 60-foot maw through which two fans powered by 4,000-horsepower motors blew air at speeds of up to 120 miles an hour. Airplanes would be suspended in the path of the artificial wind. Transducers could convert the energy of the air hitting the plane into measurements for drag and lift.
Though engineers completed the tunnel in 1934, its finest hour was probably during World War II, when it operated virtually non-stop. Langley's historians note the importance of the tunnel:
Both the Navy and the Army quickly sent a steady stream of military aircraft to Langley for "drag cleanup tests." In the next 18 months, 18 different aircraft were tested and improved in the FST. The FST operated around the clock, seven days a week, during WWII conducting not only drag cleanup tests, but engine cooling methods, stability and control, and unexpected operational problems. Early versions of virtually every high-performance fighter aircraft were evaluated in the FST, allowing for countless design improvements that gave American pilots a critical edge in combat.
Designated a historical landmark in 1985, the tunnel remained in operation through 2009 doing various types of tests. Sadly, the demolition of the tunnel began in 2010. Below, you can take a tour of the facility as preserved in the Library of Congress' Built in America collection.